/// <summary> Processes the Expression, converting it to a SQL string.</summary>
///
/// <typeparam name="T"> Generic type parameter. </typeparam>
/// <param name="expression"> The expression. </param>
///
/// <returns> . </returns>
public QueryBuilder Process <T>(Expression <Func <T, bool> > expression)
{
var expressionVisitor = new WhereExpressionVisitor();
var filter = expressionVisitor.Visit(expression, new QueryBuilder());
return(filter);
}
/// <summary> Converts the properties to sql. </summary>
/// <param name="properties"> The properties. </param>
/// <returns> The given data converted to a sql. </returns>
public string ConvertToSql(IEnumerable<Property> properties)
{
var expression = DynamicLambdaExpressions(properties);
StringBuilder builder = new StringBuilder();
WhereExpressionVisitor whereExpressions = new WhereExpressionVisitor();
whereExpressions.Visit(expression, builder);
return builder.ToString();
}
public string GetDeleteSql <T>(Expression <Func <T, bool> > expression, out IDictionary <string, dynamic> param)
{
var context = new ExpressionVisitorContext(SqlGenerator);
var visitor = new WhereExpressionVisitor(context);
visitor.Visit(expression);
var whereSql = visitor.Condition.ToSql(SqlGenerator);
param = context.Parameters;
var targetMapper = TypeMapperCache.GetTypeMapper(typeof(T));
return(SqlGenerator.GetDeleteSql(targetMapper, null, whereSql));
}
public string GetUpdateSql <T>(Expression <Func <T, bool> > expression, Expression <Func <T, object> > paramInput, object value, out IDictionary <string, dynamic> paramOuput)
{
var context = new ExpressionVisitorContext(SqlGenerator);
var whereVisitor = new WhereExpressionVisitor(context);
whereVisitor.Visit(expression);
var whereSql = whereVisitor.Condition.ToSql(SqlGenerator);
var setVisitor = new MemberExpressionVisitor(context);
setVisitor.Visit(paramInput);
var setSql = string.Format("{0} = {1}", setVisitor.Column.ToSql(SqlGenerator), context.AddParameter(value));
paramOuput = context.Parameters;
return(SqlGenerator.GetUpdateSql(TypeMapperCache.GetTypeMapper(typeof(T)), setSql, whereSql));
}
public string GetUpdateSql <T>(Expression <Func <T, bool> > expression, IDictionary <Expression <Func <T, object> >, object> paramInput, out IDictionary <string, dynamic> paramOuput)
{
var context = new ExpressionVisitorContext(SqlGenerator);
var whereVisitor = new WhereExpressionVisitor(context);
whereVisitor.Visit(expression);
var whereSql = whereVisitor.Condition.ToSql(SqlGenerator);
var setVisitor = new MemberExpressionVisitor(context);
var setSql = new StringBuilder();
foreach (KeyValuePair <Expression <Func <T, object> >, object> item in paramInput)
{
setVisitor.Visit(item.Key);
setSql.AppendFormat("{0} = {1},", setVisitor.Column.ToSql(SqlGenerator), context.AddParameter(item.Value));
}
paramOuput = context.Parameters;
return(SqlGenerator.GetUpdateSql(TypeMapperCache.GetTypeMapper(typeof(T)), setSql.Remove(setSql.Length - 1, 1).ToString(), whereSql));
}
/// <summary>
/// 创建 UPDATE 命令
/// </summary>
/// <param name="tree">查询语义</param>
/// <param name="context">解析SQL命令上下文</param>
/// <returns></returns>
protected override DbRawCommand TranslateUpdateCommand <T>(DbQueryUpdateTree tree, ITranslateContext context)
{
ISqlBuilder builder = this.CreateSqlBuilder(context);
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
builder.Append("UPDATE ");
builder.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
builder.Append(" t0");
if (tree.Entity != null)
{
object entity = tree.Entity;
ISqlBuilder whereBuilder = this.CreateSqlBuilder(context);
bool useKey = false;
int length = 0;
builder.AppendNewLine(" SET");
foreach (var item in typeRuntime.Members)
{
var m = item as FieldAccessorBase;
if (m == null || !m.IsDbField)
{
continue;
}
if (m.Column != null && m.Column.IsIdentity)
{
goto LABEL; // Fix issue# 自增列同时又是主键
}
builder.AppendMember("t0", m.Member, typeRuntime.Type);
builder.Append(" = ");
LABEL:
var value = m.Invoke(entity);
var seg = this.Constor.GetSqlValueWidthDefault(value, context, m.Column);
if (m.Column == null || !m.Column.IsIdentity)
{
builder.Append(seg);
length = builder.Length;
builder.Append(',');
builder.AppendNewLine();
}
if (m.Column != null && m.Column.IsKey)
{
useKey = true;
whereBuilder.AppendMember("t0", m.Member, typeRuntime.Type);
whereBuilder.Append(" = ");
whereBuilder.Append(seg);
whereBuilder.Append(" AND ");
}
}
if (!useKey)
{
throw new XFrameworkException("Update<T>(T value) require T must have key column.");
}
builder.Length = length;
whereBuilder.Length -= 5;
builder.AppendNewLine();
builder.Append("WHERE ");
builder.Append(whereBuilder);
}
else if (tree.Expression != null)
{
AliasGenerator ag = this.PrepareTableAlias(tree.Select, context.AliasPrefix);
DbExpressionVisitor visitor = null;
var cmd = new DbSelectCommand(context, ag, tree.Select.SelectHasMany);
if (tree.Select.Joins != null)
{
visitor = new JoinExpressionVisitor(ag, cmd.JoinFragment);
visitor.Visit(tree.Select.Joins);
}
cmd.WhereFragment.AppendNewLine();
cmd.WhereFragment.AppendNewLine("SET");
visitor = new UpdateExpressionVisitor(ag, cmd.WhereFragment);
visitor.Visit(tree.Expression);
if (tree.Select.Wheres != null)
{
visitor = new WhereExpressionVisitor(ag, cmd.WhereFragment);
visitor.Visit(tree.Select.Wheres);
cmd.AddNavMembers(visitor.NavMembers);
}
builder.Append(cmd.CommandText);
}
builder.Append(';');
return(new DbRawCommand(builder.ToString(), builder.TranslateContext != null ? builder.TranslateContext.Parameters : null, System.Data.CommandType.Text));
}
/// <summary>
/// 创建 DELETE 命令
/// </summary>
/// <param name="tree">查询语义</param>
/// <param name="context">解析SQL命令上下文</param>
/// <returns></returns>
protected override DbRawCommand TranslateDeleteCommand <T>(DbQueryDeleteTree tree, ITranslateContext context)
{
ISqlBuilder builder = this.CreateSqlBuilder(context);
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
builder.Append("DELETE t0 FROM ");
builder.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
builder.Append(" t0 ");
if (tree.Entity != null)
{
if (typeRuntime.KeyMembers == null || typeRuntime.KeyMembers.Count == 0)
{
throw new XFrameworkException("Delete<T>(T value) require entity must have key column.");
}
object entity = tree.Entity;
builder.AppendNewLine();
builder.Append("WHERE ");
foreach (FieldAccessorBase m in typeRuntime.KeyMembers)
{
var value = m.Invoke(entity);
var sqlExpression = this.Constor.GetSqlValue(value, context, m.Column);
builder.AppendMember("t0", m.Member, typeRuntime.Type);
builder.Append(" = ");
builder.Append(sqlExpression);
builder.Append(" AND ");
}
builder.Length -= 5;
}
else if (tree.Select != null)
{
AliasGenerator ag = this.PrepareTableAlias(tree.Select, context.AliasPrefix);
var cmd = new DbSelectCommand(context, ag, tree.Select.SelectHasMany);
// 标记当前解析上下文是删除语句产生的
var isDelete = ((MySqlTranslateContext)context).IsDelete;
((MySqlTranslateContext)context).IsDelete = true;
if (tree.Select.Joins != null)
{
var visitor = new JoinExpressionVisitor(ag, cmd.JoinFragment);
visitor.Visit(tree.Select.Joins);
}
if (tree.Select.Wheres != null)
{
var visitor = new WhereExpressionVisitor(ag, cmd.WhereFragment);
visitor.Visit(tree.Select.Wheres);
cmd.AddNavMembers(visitor.NavMembers);
}
builder.Append(cmd.CommandText);
// 恢复当前解析上下文的删除标记
((MySqlTranslateContext)context).IsDelete = isDelete;
}
builder.Append(';');
return(new DbRawCommand(builder.ToString(), builder.TranslateContext != null ? builder.TranslateContext.Parameters : null, System.Data.CommandType.Text));
}
// 解译 SELECT 语句
private DbRawCommand TranslateSelectCommandImpl(DbQuerySelectTree tree, int indent, bool isOutermost, ITranslateContext context)
{
// 说明：
// 1.OFFSET 前必须要有 'ORDER BY'，即 'Skip' 子句前必须使用 'OrderBy' 子句
// 2.在有聚合函数的<MAX,MIN...>情况下，如果有 'Distinct' 'GroupBy' 'Skip' 'Take' 子句，则需要使用嵌套查询
// 3.'Any' 子句将翻译成 IF EXISTS...
// 4.分组再分页时需要使用嵌套查询，此时子查询不需要 'OrderBy' 子句，但最外层则需要
// 5.'Skip' 'Take' 子句视为语义结束符，在其之后的子句将使用嵌套查询
// 6.导航属性中有 1:n 关系的，需要使用嵌套查询，否则分页查询会有问题
// 8.如果只有 Skip 没有 Take，则使用 Row_Number() Over()分页语法，其它使用 LIMIT ## OFFSET 语法
// 导航属性中有1:n关系，只统计主表
// 例：AccountList = a.Client.AccountList,
var subquery = tree.Subquery as DbQuerySelectTree;
if (tree.SelectHasMany && subquery != null && subquery.Aggregate != null)
{
tree = subquery;
}
var srcDbExpressionType = context.CurrentExpressionType;
var srcIsOutmost = context.CurrentIsOutermost;
if (srcDbExpressionType == null)
{
context.CurrentExpressionType = DbExpressionType.Select;
}
if (srcIsOutmost == null || !isOutermost)
{
context.CurrentIsOutermost = isOutermost;
}
bool useAggregate = tree.Aggregate != null;
// 没有聚合函数或者使用 'Skip' 子句，则解析OrderBy
// 导航属性如果使用嵌套，除非有 TOP 或者 OFFSET 子句，否则不能用ORDER BY
// 第一层的表别名
string alias = context != null && !string.IsNullOrEmpty(context.AliasPrefix) ? (context.AliasPrefix + "0") : "t0";
bool useSubquery = tree.HasDistinct || tree.GroupBy != null || tree.Skip > 0 || tree.Take > 0;
bool useOrderBy = (!useAggregate || tree.Skip > 0) && !tree.HasAny && (!tree.SelectHasMany || (tree.Skip > 0 || tree.Take > 0));
AliasGenerator ag = this.PrepareTableAlias(tree, context != null ? context.AliasPrefix : null);
var result = new DbSelectCommand(context, ag, tree.SelectHasMany);
ISqlBuilder jf = result.JoinFragment;
ISqlBuilder wf = result.WhereFragment;
ISqlBuilder sf = null;
jf.Indent = indent;
#region 嵌套查询
if (useAggregate && useSubquery)
{
// SELECT
jf.Append("SELECT ");
jf.AppendNewLine();
// SELECT COUNT(1)
var visitor = new AggregateExpressionVisitor(ag, jf, tree.GroupBy, alias);
visitor.Visit(tree.Aggregate);
result.AddNavMembers(visitor.NavMembers);
// SELECT COUNT(1) FROM
jf.AppendNewLine();
jf.Append("FROM ( ");
indent += 1;
jf.Indent = indent;
context.CurrentIsOutermost = false;
}
#endregion
#region 择子句
// SELECT 子句
if (jf.Indent > 0)
{
jf.AppendNewLine();
}
jf.Append("SELECT ");
if (tree.HasAny)
{
jf.Append("CASE WHEN COUNT(1) = 1 THEN 1 ELSE 0 END FROM (");
indent += 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append("SELECT 1 ");
}
if (useAggregate && !useSubquery)
{
// 如果有聚合函数，并且不是嵌套的话，则直接使用SELECT <MAX,MIN...>，不需要解析选择的字段
jf.AppendNewLine();
var visitor_ = new AggregateExpressionVisitor(ag, jf, tree.GroupBy, null);
visitor_.Visit(tree.Aggregate);
result.AddNavMembers(visitor_.NavMembers);
}
else
{
// DISTINCT 子句
if (tree.HasDistinct)
{
jf.Append("DISTINCT ");
}
#region 择字段
if (!tree.HasAny)
{
// SELECT 范围
ColumnExpressionVisitor visitor = null;
if (tree.Skip > 0 && tree.Take == 0)
{
sf = this.CreateSqlBuilder(context);
sf.Indent = jf.Indent + 1;
visitor = new ColumnExpressionVisitor(ag, sf, tree);
visitor.Visit(tree.Select);
}
else
{
visitor = new ColumnExpressionVisitor(ag, jf, tree);
visitor.Visit(tree.Select);
}
result.SelectedColumns = visitor.SelectedColumns;
result.SelectedColumnText = visitor.SelectedColumnText;
result.SelectedNavs = visitor.SelectedNavDescriptors;
result.AddNavMembers(visitor.NavMembers);
if (sf != null)
{
// 第一层嵌套
int index = 0;
jf.AppendNewLine();
foreach (var column in result.SelectedColumns)
{
jf.AppendMember(alias, column.Name);
jf.AppendAs(column.NewName);
index += 1;
if (index < result.SelectedColumns.Count)
{
jf.Append(',');
jf.AppendNewLine();
}
}
jf.AppendNewLine();
jf.Append("FROM(");
// 第二层嵌套
indent += 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append("SELECT");
jf.Append(sf);
jf.Append(',');
jf.AppendNewLine();
if (tree.OrderBys == null || tree.OrderBys.Count == 0)
{
throw new XFrameworkException("The method 'OrderBy' must be called before 'Skip'.");
}
jf.Append("ROW_NUMBER() OVER(");
var visitor3 = new OrderByExpressionVisitor(ag, jf, tree.GroupBy, null);
visitor3.Visit(tree.OrderBys, false);
result.AddNavMembers(visitor3.NavMembers);
jf.Append(") Row_Number0");
}
}
#endregion
}
#endregion
#region 顺序解析
// FROM 子句
jf.AppendNewLine();
jf.Append("FROM ");
if (tree.Subquery != null)
{
// 子查询
jf.Append("(");
var cmd = this.TranslateSelectCommandImpl(tree.Subquery, indent + 1, false, context);
jf.Append(cmd.CommandText);
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
jf.Append(' ');
}
else if (tree.FromSql != null)
{
if (tree.FromSql.DbContext == null)
{
tree.FromSql.DbContext = context.DbContext;
}
DbRawSql rawSql = tree.FromSql;
// 解析参数
object[] args = null;
if (rawSql.Parameters != null)
{
args = rawSql.Parameters.Select(x => this.Constor.GetSqlValue(x, context)).ToArray();
}
string sql = rawSql.CommandText;
if (args != null && args.Length > 0)
{
sql = string.Format(sql, args);
}
// 子查询
jf.Append('(');
var cmd = new DbRawCommand(sql, context.Parameters, CommandType.Text);
jf.Append(cmd.CommandText);
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
jf.Append(' ');
}
else
{
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(tree.From);
jf.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
jf.Append(' ');
jf.Append(alias);
jf.Append(' ');
}
// LEFT<INNER> JOIN 子句
if (tree.Joins != null)
{
var visitor = new JoinExpressionVisitor(ag, jf);
visitor.Visit(tree.Joins);
}
wf.Indent = jf.Indent;
// WHERE 子句
if (tree.Wheres != null)
{
var visitor = new WhereExpressionVisitor(ag, wf);
visitor.Visit(tree.Wheres);
result.AddNavMembers(visitor.NavMembers);
}
// GROUP BY 子句
if (tree.GroupBy != null)
{
var visitor = new GroupByExpressionVisitor(ag, wf);
visitor.Visit(tree.GroupBy);
result.AddNavMembers(visitor.NavMembers);
}
// HAVING 子句
if (tree.Havings != null)
{
var visitor = new HavingExpressionVisitor(ag, wf, tree.GroupBy);
visitor.Visit(tree.Havings);
result.AddNavMembers(visitor.NavMembers);
}
// ORDER 子句
if (tree.OrderBys != null && tree.OrderBys.Count > 0 && useOrderBy)// && !groupByPaging)
{
var visitor = new OrderByExpressionVisitor(ag, wf, tree.GroupBy, null);
visitor.Visit(tree.OrderBys);
result.AddNavMembers(visitor.NavMembers);
}
#endregion
#region 分页查询
// LIMIT 子句可以被用于强制 SELECT 语句返回指定的记录数。
// LIMIT 接受一个或两个数字参数。参数必须是一个整数常量。如果给定两个参数，第一个参数指定第一个返回记录行的偏移量，第二个参数指定返回记录行的最大数目。
// 初始记录行的偏移量是 0(而不是 1)： 为了与 PostgreSQL 兼容，MySQL 也支持句法： LIMIT # OFFSET #。
// Limit n,-1 语法不支持，使用ROW_Number()语法代替
if (tree.Take > 0)
{
wf.AppendNewLine().AppendFormat("LIMIT {0}", this.Constor.GetSqlValue(tree.Take, context));
wf.AppendFormat(" OFFSET {0}", this.Constor.GetSqlValue(tree.Skip, context));
}
#endregion
#region 嵌套查询
if (useAggregate && useSubquery)
{
result.CombineFragments();
indent -= 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
}
#endregion
#region 嵌套导航
// TODO Include 从表，没分页，OrderBy 报错
//if (tree.HasMany && subquery != null && subquery.OrderBys.Count > 0 && subquery.Aggregate == null && !(subquery.Skip > 0 || subquery.Take > 0))
if (tree.SelectHasMany && subquery.Aggregate == null &&
subquery != null && subquery.OrderBys != null && subquery.OrderBys.Count > 0 && !(subquery.Skip > 0 || subquery.Take > 0))
{
result.CombineFragments();
var visitor = new OrderByExpressionVisitor(ag, jf, null, null);
visitor.Visit(subquery.OrderBys);
}
#endregion
#region 并集查询
// UNION 子句
if (tree.Unions != null && tree.Unions.Count > 0)
{
result.CombineFragments();
for (int index = 0; index < tree.Unions.Count; index++)
{
jf.AppendNewLine();
jf.Append("UNION ALL");
if (indent == 0)
{
jf.AppendNewLine();
}
DbRawCommand cmd = this.TranslateSelectCommandImpl(tree.Unions[index], indent, isOutermost, context);
jf.Append(cmd.CommandText);
}
}
#endregion
#region 分页查询
if (sf != null)
{
// 合并 WHERE
result.CombineFragments();
indent -= 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
jf.AppendNewLine();
jf.Append("WHERE ");
if (tree.Skip > 0)
{
jf.AppendMember(alias, "Row_Number0");
jf.Append(" > ");
jf.Append(this.Constor.GetSqlValue(tree.Skip, context));
}
}
#endregion
#region Any 子句
// 'Any' 子句
if (tree.HasAny)
{
// 产生 WHERE 子句
result.CombineFragments();
// 如果没有分页，则显式指定只查一笔记录
if (tree.Take == 0 && tree.Skip == 0)
{
jf.AppendNewLine();
jf.Append("LIMIT 0,1");
}
indent -= 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
}
#endregion
#region 还原状态
context.CurrentExpressionType = srcDbExpressionType;
context.CurrentIsOutermost = srcIsOutmost;
#endregion
return(result);
}
/// <summary>
/// 创建 UPDATE 命令
/// </summary>
/// <param name="tree">查询语义</param>
/// <param name="context">解析SQL命令上下文</param>
/// <returns></returns>
protected override DbRawCommand TranslateUpdateCommand <T>(DbQueryUpdateTree tree, ITranslateContext context)
{
ISqlBuilder builder = this.CreateSqlBuilder(context);
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
builder.Append("UPDATE ");
builder.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
builder.Append(" t0 SET");
builder.AppendNewLine();
if (tree.Entity != null)
{
object entity = tree.Entity;
ISqlBuilder whereBuilder = this.CreateSqlBuilder(context);
bool useKey = false;
int length = 0;
foreach (var item in typeRuntime.Members)
{
var m = item as FieldAccessorBase;
if (m == null || !m.IsDbField)
{
continue;
}
if (m.Column != null && m.Column.IsIdentity)
{
goto LABEL; // Fix issue# 自增列同时又是主键
}
builder.AppendMember(null, m.Member, typeRuntime.Type);
builder.Append(" = ");
LABEL:
if (m.Column == null || !m.Column.IsIdentity)
{
var value = m.Invoke(entity);
var sqlExpression = this.Constor.GetSqlValueWidthDefault(value, context, m.Column);
builder.Append(sqlExpression);
length = builder.Length;
builder.Append(',');
builder.AppendNewLine();
}
if (m.Column != null && m.Column.IsKey)
{
useKey = true;
}
}
if (!useKey)
{
throw new XFrameworkException("Update<T>(T value) require T must have key column.");
}
// ORACLE 需要注意参数顺序问题
int index = -1;
foreach (FieldAccessorBase m in typeRuntime.KeyMembers)
{
var column = m.Column;
var value = m.Invoke(entity);
var seg = this.Constor.GetSqlValueWidthDefault(value, context, column);
index += 1;
whereBuilder.AppendMember(null, m.Member, typeRuntime.Type);
whereBuilder.Append(" = ");
whereBuilder.Append(seg);
if (index < typeRuntime.KeyMembers.Count - 1)
{
whereBuilder.Append(" AND ");
}
}
builder.Length = length;
builder.AppendNewLine();
builder.Append("WHERE ");
builder.Append(whereBuilder);
}
else if (tree.Expression != null)
{
// SELECT 表达式
LambdaExpression lambda = tree.Expression as LambdaExpression;
var body = lambda.Body;
Expression expression = null;
if (body.NodeType == ExpressionType.MemberInit)
{
var initExpression = body as MemberInitExpression;
var bindings = new List <MemberBinding>(initExpression.Bindings);
foreach (var m in typeRuntime.KeyMembers)
{
var member = Expression.MakeMemberAccess(lambda.Parameters[0], m.Member);
var binding = Expression.Bind(m.Member, member);
if (!bindings.Any(x => x.Member == m.Member))
{
bindings.Add(binding);
}
}
expression = Expression.MemberInit(initExpression.NewExpression, bindings);
}
else if (body.NodeType == ExpressionType.New)
{
var newExpression = body as NewExpression;
var bindings = new List <MemberBinding>();
for (int index = 0; index < newExpression.Members.Count; index++)
{
var m = (FieldAccessorBase)typeRuntime.Members.FirstOrDefault(a => a is FieldAccessorBase && (
a.Name == newExpression.Members[index].Name ||
((FieldAccessorBase)a).Column != null && ((FieldAccessorBase)a).Column.Name == newExpression.Members[index].Name));
if (m == null)
{
throw new XFrameworkException("Member {0}.{1} not found.", typeRuntime.Type.Name, newExpression.Members[index].Name);
}
var binding = Expression.Bind(m.Member, newExpression.Arguments[index].Type != m.CLRType
? Expression.Convert(newExpression.Arguments[index], m.CLRType)
: newExpression.Arguments[index]);
bindings.Add(binding);
}
foreach (var m in typeRuntime.KeyMembers)
{
var member = Expression.MakeMemberAccess(lambda.Parameters[0], m.Member);
var binding = Expression.Bind(m.Member, member);
if (!bindings.Any(x => x.Member == m.Member))
{
bindings.Add(binding);
}
}
var newExpression2 = Expression.New(typeRuntime.Constructor.Member);
expression = Expression.MemberInit(newExpression2, bindings);
}
// 解析查询以确定是否需要嵌套
tree.Select.Select = new DbExpression(DbExpressionType.Select, expression);
var cmd = (DbSelectCommand)this.TranslateSelectCommand(tree.Select, 0, false, this.CreateTranslateContext(context.DbContext));
if ((cmd.NavMembers != null && cmd.NavMembers.Count > 0) || (tree.Select.Joins != null && tree.Select.Joins.Count > 0))
{
// 无法使用 DISTINCT, GROUP BY 等子句从视图中选择 ROWID 或采样。UPDATE 不能用rowid
// 有导航属性或者关联查询，使用 MERGE INTO 语法。要求必须有主键
if (typeRuntime.KeyMembers == null || typeRuntime.KeyMembers.Count == 0)
{
throw new XFrameworkException("Update<T>(Expression<Func<T, object>> updateExpression) require entity must have key column.");
}
builder.Length = 0;
builder.Append("MERGE INTO ");
builder.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
builder.AppendNewLine(" t0");
builder.Append("USING (");
cmd = (DbSelectCommand)this.TranslateSelectCommand(tree.Select, 1, false, context);
builder.AppendNewLine(cmd.CommandText);
builder.Append(") t1 ON (");
foreach (var m in typeRuntime.KeyMembers)
{
builder.AppendMember("t0", m.Member, typeRuntime.Type);
builder.Append(" = ");
builder.AppendMember("t1", m.Member, typeRuntime.Type);
builder.Append(" AND ");
}
builder.Length -= 5;
builder.Append(')');
// UPDATE
builder.AppendNewLine();
builder.AppendNewLine("WHEN MATCHED THEN UPDATE SET ");
// SET 字段
var visitor = new OracleUpdateExpressionVisitor(null, builder);
visitor.Visit(tree.Expression);
}
else
{
// 直接 SQL 的 UPDATE 语法
DbExpressionVisitor visitor = null;
AliasGenerator ag = this.PrepareTableAlias(tree.Select, context.AliasPrefix);
visitor = new UpdateExpressionVisitor(ag, builder);
visitor.Visit(tree.Expression);
if (tree.Select.Wheres != null)
{
visitor = new WhereExpressionVisitor(ag, builder);
visitor.Visit(tree.Select.Wheres);
}
}
}
builder.Append(';');
return(new DbRawCommand(builder.ToString(), builder.TranslateContext != null ? builder.TranslateContext.Parameters : null, System.Data.CommandType.Text));
}
/// <summary>
/// 创建 DELETE 命令
/// </summary>
/// <param name="tree">查询语义</param>
/// <param name="context">解析SQL命令上下文</param>
/// <returns></returns>
protected override DbRawCommand TranslateDeleteCommand <T>(DbQueryDeleteTree tree, ITranslateContext context)
{
ISqlBuilder builder = this.CreateSqlBuilder(context);
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
builder.Append("DELETE FROM ");
builder.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
builder.Append(" t0 ");
if (tree.Entity != null)
{
if (typeRuntime.KeyMembers == null || typeRuntime.KeyMembers.Count == 0)
{
throw new XFrameworkException("Delete<T>(T value) require entity must have key column.");
}
object entity = tree.Entity;
builder.AppendNewLine();
builder.Append("WHERE ");
foreach (FieldAccessorBase m in typeRuntime.KeyMembers)
{
var value = m.Invoke(entity);
var sqlExpression = this.Constor.GetSqlValue(value, context, m.Column);
builder.AppendMember("t0", m.Member, typeRuntime.Type);
builder.Append(" = ");
builder.Append(sqlExpression);
builder.Append(" AND ");
}
builder.Length -= 5;
}
else if (tree.Select != null)
{
// 解析查询用来确定是否需要嵌套
var cmd = this.TranslateSelectCommand(tree.Select, 0, false, this.CreateTranslateContext(context.DbContext)) as DbSelectCommand;
if ((cmd.NavMembers != null && cmd.NavMembers.Count > 0) || (tree.Select.Joins != null && tree.Select.Joins.Count > 0))
{
// 最外层仅选择 RowID 列
var outQuery = tree.Select;
outQuery.Select = new DbExpression(DbExpressionType.Select, Expression.Constant("t0.RowId", typeof(string)));
var iterator = outQuery;
while (iterator.Subquery != null)
{
var subquery = new OracleDbQuerySelectTree(iterator.Subquery);
iterator.Subquery = subquery;
iterator = subquery;
}
// 解析成 RowId IN 结构
cmd = (DbSelectCommand)this.TranslateSelectCommand(tree.Select, 1, false, context);
builder.Append("WHERE t0.RowId IN(");
builder.AppendNewLine(cmd.CommandText);
builder.Append(')');
}
else
{
AliasGenerator ag = this.PrepareTableAlias(tree.Select, context.AliasPrefix);
if (tree.Select.Joins != null)
{
var visitor = new JoinExpressionVisitor(ag, builder);
visitor.Visit(tree.Select.Joins);
}
if (tree.Select.Wheres != null)
{
var visitor = new WhereExpressionVisitor(ag, builder);
visitor.Visit(tree.Select.Wheres);
}
}
}
builder.Append(';');
return(new DbRawCommand(builder.ToString(), builder.TranslateContext != null ? builder.TranslateContext.Parameters : null, System.Data.CommandType.Text));
}
/// <summary>
/// 解析 SELECT 命令
/// </summary>
/// <param name="tree">查询语义</param>
/// <param name="indent">缩进</param>
/// <param name="isOutermost">是否是最外层查询</param>
/// <param name="context">解析SQL命令上下文</param>
/// <returns></returns>
protected override DbRawCommand TranslateSelectCommand(DbQuerySelectTree tree, int indent, bool isOutermost, ITranslateContext context)
{
// 说明：
// 1.OFFSET 前必须要有 'ORDER BY'，即 'Skip' 子句前必须使用 'OrderBy' 子句
// 2.在有聚合函数的<MAX,MIN...>情况下，如果有 'Distinct' 'GroupBy' 'Skip' 'Take' 子句，则需要使用嵌套查询
// 3.'Any' 子句将翻译成 IF EXISTS...
// 4.分组再分页时需要使用嵌套查询，此时子查询不需要 'OrderBy' 子句，但最外层则需要
// 5.'Skip' 'Take' 子句视为语义结束符，在其之后的子句将使用嵌套查询
// 6.导航属性中有 1:n 关系的，需要使用嵌套查询，否则分页查询会有问题
// 8.如果有分页，则使用嵌套
// 9.如果有分页还有OrderBy，则使用嵌套的嵌套
// 导航属性中有1:n关系，只统计主表
// 例：AccountList = a.Client.AccountList,
var subquery = tree.Subquery as DbQuerySelectTree;
if (tree.SelectHasMany && subquery != null && subquery.Aggregate != null)
{
tree = subquery;
}
var srcDbExpressionType = context.CurrentExpressionType;
var srcIsOutmost = context.CurrentIsOutermost;
if (srcDbExpressionType == null)
{
context.CurrentExpressionType = DbExpressionType.Select;
}
if (srcIsOutmost == null || !isOutermost)
{
context.CurrentIsOutermost = isOutermost;
}
bool useAggregate = tree.Aggregate != null;
// 没有聚合函数或者使用 'Skip' 子句，则解析OrderBy
// 导航属性如果使用嵌套，除非有 TOP 或者 OFFSET 子句，否则不能用ORDER BY
// 第一层的表别名
string alias = context != null && !string.IsNullOrEmpty(context.AliasPrefix) ? (context.AliasPrefix + "0") : "t0";
bool useSubquery = tree.HasDistinct || tree.GroupBy != null || tree.Skip > 0 || tree.Take > 0;
bool useOrderBy = (!useAggregate || tree.Skip > 0) && !tree.HasAny && (!tree.SelectHasMany || (tree.Skip > 0 || tree.Take > 0));
AliasGenerator ag = this.PrepareTableAlias(tree, context != null ? context.AliasPrefix : null);
var result = new DbSelectCommand(context, ag, tree.SelectHasMany);
ISqlBuilder jf = result.JoinFragment;
ISqlBuilder wf = result.WhereFragment;
(jf as OracleSqlBuilder).UseQuote = isOutermost;
jf.Indent = indent;
#region 嵌套查询
if (useAggregate && useSubquery)
{
// SELECT
jf.Append("SELECT ");
jf.AppendNewLine();
// SELECT COUNT(1)
var visitor = new AggregateExpressionVisitor(ag, jf, tree.GroupBy, alias);
visitor.Visit(tree.Aggregate);
result.AddNavMembers(visitor.NavMembers);
// SELECT COUNT(1) FROM
jf.AppendNewLine();
jf.Append("FROM ( ");
indent += 1;
jf.Indent = indent;
(jf as OracleSqlBuilder).UseQuote = false;
context.CurrentIsOutermost = false;
}
#endregion
#region 择子句
// SELECT 子句
if (jf.Indent > 0)
{
jf.AppendNewLine();
}
jf.Append("SELECT ");
if (tree.HasAny)
{
jf.Append("CASE WHEN COUNT(1) = 1 THEN 1 ELSE 0 END FROM (");
indent += 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append("SELECT 1 ");
}
if (useAggregate && !useSubquery)
{
// 如果有聚合函数，并且不是嵌套的话，则直接使用SELECT <MAX,MIN...>，不需要解析选择的字段
jf.AppendNewLine();
var visitor = new AggregateExpressionVisitor(ag, jf, tree.GroupBy, null);
visitor.Visit(tree.Aggregate);
result.AddNavMembers(visitor.NavMembers);
}
else
{
// DISTINCT 子句
if (tree.HasDistinct)
{
jf.Append("DISTINCT ");
}
#region 择字段
if (!tree.HasAny)
{
// SELECT 范围
ISqlBuilder sf = this.CreateSqlBuilder(context);
sf.Indent = jf.Indent + ((tree.Skip > 0 || tree.Take > 0) ? 2 : 0);
(sf as OracleSqlBuilder).UseQuote = (tree.Skip > 0 || tree.Take > 0) ? false : (jf as OracleSqlBuilder).UseQuote;
var visitor = new OracleColumnExpressionVisitor(ag, sf, tree);
visitor.Visit(tree.Select);
result.SelectedColumns = visitor.SelectedColumns;
result.SelectedColumnText = visitor.SelectedColumnText;
result.SelectedNavs = visitor.SelectedNavDescriptors;
result.AddNavMembers(visitor.NavMembers);
// 分页，产生两层嵌套
if (tree.Skip > 0 || tree.Take > 0)
{
// 第一层嵌套
int index = 0;
jf.AppendNewLine();
foreach (var column in result.SelectedColumns)
{
jf.AppendMember(alias, column.Name);
jf.AppendAs(column.NewName);
index += 1;
if (index < result.SelectedColumns.Count)
{
jf.Append(',');
jf.AppendNewLine();
}
}
jf.AppendNewLine();
jf.Append("FROM(");
// 第二层嵌套
indent += 1;
isOutermost = false;
jf.Indent = indent;
(jf as OracleSqlBuilder).UseQuote = isOutermost;
jf.AppendNewLine();
jf.Append("SELECT");
jf.AppendNewLine();
foreach (var column in result.SelectedColumns)
{
jf.AppendMember(alias, column.NewName);
jf.AppendAs(column.NewName);
jf.Append(',');
jf.AppendNewLine();
}
jf.Append("ROWNUM");
jf.AppendAs("Row_Number0");
jf.AppendNewLine();
jf.Append("FROM(");
// 第三层嵌套
indent += 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append("SELECT");
}
jf.Append(sf);
}
#endregion
}
#endregion
#region 顺序解析
// FROM 子句
jf.AppendNewLine();
jf.Append("FROM ");
if (tree.Subquery != null)
{
// 子查询
jf.Append('(');
DbRawCommand cmd = this.TranslateSelectCommand(tree.Subquery, indent + 1, false, context);
jf.Append(cmd.CommandText);
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
jf.Append(' ');
}
else if (tree.FromSql != null)
{
if (tree.FromSql.DbContext == null)
{
tree.FromSql.DbContext = context.DbContext;
}
DbRawSql rawSql = tree.FromSql;
// 解析参数
object[] args = null;
if (rawSql.Parameters != null)
{
args = rawSql.Parameters.Select(x => this.Constor.GetSqlValue(x, context)).ToArray();
}
string sql = rawSql.CommandText;
if (args != null && args.Length > 0)
{
sql = string.Format(sql, args);
}
// 子查询
jf.Append('(');
var cmd = new DbRawCommand(sql, context.Parameters, CommandType.Text);
jf.Append(cmd.CommandText);
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
jf.Append(' ');
}
else
{
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(tree.From);
jf.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
jf.Append(' ');
jf.Append(alias);
jf.Append(' ');
}
// LEFT<INNER> JOIN 子句
if (tree.Joins != null)
{
var visitor = new JoinExpressionVisitor(ag, jf);
visitor.Visit(tree.Joins);
}
wf.Indent = jf.Indent;
// WHERE 子句
if (tree.Wheres != null)
{
var visitor = new WhereExpressionVisitor(ag, wf);
visitor.Visit(tree.Wheres);
result.AddNavMembers(visitor.NavMembers);
}
// GROUP BY 子句
if (tree.GroupBy != null)
{
var visitor = new GroupByExpressionVisitor(ag, wf);
visitor.Visit(tree.GroupBy);
result.AddNavMembers(visitor.NavMembers);
}
// HAVING 子句
if (tree.Havings != null)
{
var visitor = new HavingExpressionVisitor(ag, wf, tree.GroupBy);
visitor.Visit(tree.Havings);
result.AddNavMembers(visitor.NavMembers);
}
// ORDER 子句
if (tree.OrderBys != null && tree.OrderBys.Count > 0 && useOrderBy)
{
var visitor = new OrderByExpressionVisitor(ag, wf, tree.GroupBy, null);
visitor.Visit(tree.OrderBys);
result.AddNavMembers(visitor.NavMembers);
}
#endregion
#region 嵌套查询
if (useAggregate && useSubquery)
{
result.CombineFragments();
indent -= 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
}
#endregion
#region 嵌套导航
// TODO Include 从表，没分页，OrderBy 报错
if (tree.SelectHasMany && subquery.Aggregate == null &&
subquery != null && subquery.OrderBys != null && subquery.OrderBys.Count > 0 && !(subquery.Skip > 0 || subquery.Take > 0))
{
// OrderBy("a.CloudServer.CloudServerName");
result.CombineFragments();
var visitor = new OrderByExpressionVisitor(ag, jf, null, null);
visitor.Visit(subquery.OrderBys);
}
#endregion
#region 并集查询
// UNION 子句
if (tree.Unions != null && tree.Unions.Count > 0)
{
result.CombineFragments();
for (int index = 0; index < tree.Unions.Count; index++)
{
jf.AppendNewLine();
jf.Append("UNION ALL");
if (indent == 0)
{
jf.AppendNewLine();
}
DbRawCommand cmd2 = this.TranslateSelectCommand(tree.Unions[index], indent, isOutermost, context);
jf.Append(cmd2.CommandText);
}
}
#endregion
#region 分页查询
if (tree.Take > 0 || tree.Skip > 0)
{
// 合并 WHERE
result.CombineFragments();
indent -= 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
indent -= 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
jf.AppendNewLine();
jf.Append("WHERE ");
if (tree.Skip > 0)
{
jf.AppendMember(alias, "Row_Number0");
jf.Append(" > ");
jf.Append(this.Constor.GetSqlValue(tree.Skip, context));
}
if (tree.Take > 0)
{
if (tree.Skip > 0)
{
jf.Append(" AND ");
}
jf.AppendMember(alias, "Row_Number0");
jf.Append(" <= ");
jf.Append(this.Constor.GetSqlValue((tree.Skip + tree.Take), context));
}
}
#endregion
#region Any子句
// 'Any' 子句
if (tree.HasAny)
{
// 产生 WHERE 子句
result.CombineFragments();
// 如果没有分页，则显式指定只查一笔记录
if (tree.Take == 0 && tree.Skip == 0)
{
if (tree.Wheres != null && tree.Wheres.Count > 0)
{
jf.Append(" AND ROWNUM <= 1");
}
else
{
jf.AppendNewLine();
jf.Append("WHERE ROWNUM <= 1");
}
}
indent -= 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
}
#endregion
#region 还原状态
context.CurrentExpressionType = srcDbExpressionType;
context.CurrentIsOutermost = srcIsOutmost;
#endregion
return(result);
}
/// <summary>
/// 解析 SELECT 命令
/// </summary>
/// <param name="tree">查询语义</param>
/// <param name="indent">缩进</param>
/// <param name="isOutermost">是否外层查询，内层查询不需要结束符(;)</param>
/// <param name="context">解析上下文</param>
/// <returns></returns>
protected override DbRawCommand TranslateSelectCommand(DbQuerySelectTree tree, int indent, bool isOutermost, ITranslateContext context)
{
// 说明：
// 1.OFFSET 前必须要有 'ORDER BY'，即 'Skip' 子句前必须使用 'OrderBy' 子句
// 2.在有聚合函数的<MAX,MIN...>情况下，如果有 'Distinct' 'GroupBy' 'Skip' 'Take' 子句，则需要使用嵌套查询
// 3.'Any' 子句将翻译成 IF EXISTS...
// 4.分组再分页时需要使用嵌套查询，此时子查询不需要 'OrderBy' 子句，但最外层则需要
// 5.'Skip' 'Take' 子句视为语义结束符，在其之后的子句将使用嵌套查询
// 6.导航属性中有 1:n 关系的，需要使用嵌套查询，否则分页查询会有问题
// 导航属性中有1:n关系，只统计主表
// 例：AccountList = a.Client.AccountList,
var subquery = tree.Subquery as DbQuerySelectTree;
if (tree.SelectHasMany && subquery != null && subquery.Aggregate != null)
{
tree = subquery;
}
var srcDbExpressionType = context.CurrentExpressionType;
var srcIsOutermost = context.CurrentIsOutermost;
if (srcDbExpressionType == null)
{
context.CurrentExpressionType = DbExpressionType.Select;
}
if (srcIsOutermost == null || !isOutermost)
{
context.CurrentIsOutermost = isOutermost;
}
bool useAggregate = tree.Aggregate != null;
// 没有聚合函数或者使用 'Skip' 子句，则解析OrderBy
// 导航属性如果使用嵌套，除非有 TOP 或者 OFFSET 子句，否则不能用ORDER BY
// 第一层的表别名
string alias = context != null && !string.IsNullOrEmpty(context.AliasPrefix) ? (context.AliasPrefix + "0") : "t0";
bool useSubquery = tree.HasDistinct || tree.GroupBy != null || tree.Skip > 0 || tree.Take > 0;
bool useOrderBy = (!useAggregate || tree.Skip > 0) && !tree.HasAny && (!tree.SelectHasMany || (tree.Skip > 0 || tree.Take > 0));
AliasGenerator ag = this.PrepareTableAlias(tree, context != null ? context.AliasPrefix : null);
var result = new SqlServerDbSelectCommand(context, ag, tree.SelectHasMany);
ISqlBuilder jf = result.JoinFragment;
ISqlBuilder wf = result.WhereFragment;
jf.Indent = indent;
#region 嵌套查询
if (useAggregate && useSubquery)
{
// SELECT
jf.Append("SELECT ");
jf.AppendNewLine();
// SELECT COUNT(1)
var visitor = new AggregateExpressionVisitor(ag, jf, tree.GroupBy, alias);
visitor.Visit(tree.Aggregate);
result.AddNavMembers(visitor.NavMembers);
// SELECT COUNT(1) FROM
jf.AppendNewLine();
jf.Append("FROM ( ");
indent += 1;
jf.Indent = indent;
context.CurrentIsOutermost = false;
}
#endregion 嵌套查询
#region 择子句
// SELECT 子句
if (jf.Indent > 0)
{
jf.AppendNewLine();
}
if (tree.HasAny)
{
jf.Append("IF EXISTS(");
indent += 1;
jf.Indent = indent;
jf.AppendNewLine();
}
jf.Append("SELECT ");
if (useAggregate && !useSubquery)
{
// 如果有聚合函数，并且不是嵌套的话，则直接使用SELECT <MAX,MIN...>，不需要解析选择的字段
jf.AppendNewLine();
var visitor = new AggregateExpressionVisitor(ag, jf, tree.GroupBy, null);
visitor.Visit(tree.Aggregate);
result.AddNavMembers(visitor.NavMembers);
}
else
{
// DISTINCT 子句
if (tree.HasDistinct)
{
jf.Append("DISTINCT ");
}
// TOP 子句
if (tree.Take > 0 && tree.Skip == 0)
{
jf.AppendFormat("TOP({0})", this.Constor.GetSqlValue(tree.Take, context));
}
// Any
if (tree.HasAny)
{
jf.Append("TOP 1 1");
}
#region 字段
if (!tree.HasAny)
{
// SELECT 范围
var visitor = new ColumnExpressionVisitor(ag, jf, tree);
visitor.Visit(tree.Select);
result.SelectedColumns = visitor.SelectedColumns;
result.SelectedColumnText = visitor.SelectedColumnText;
result.SelectedNavs = visitor.SelectedNavDescriptors;
result.AddNavMembers(visitor.NavMembers);
}
#endregion 字段
}
#endregion 择子句
#region 顺序解析
// FROM 子句
jf.AppendNewLine();
jf.Append("FROM ");
if (tree.Subquery != null)
{
// 子查询
jf.Append('(');
DbRawCommand cmd = this.TranslateSelectCommand(tree.Subquery, indent + 1, false, context);
jf.Append(cmd.CommandText);
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
jf.Append(' ');
}
else if (tree.FromSql != null)
{
if (tree.FromSql.DbContext == null)
{
tree.FromSql.DbContext = context.DbContext;
}
DbRawSql rawSql = tree.FromSql;
// 解析参数
object[] args = null;
if (rawSql.Parameters != null)
{
args = rawSql.Parameters.Select(x => this.Constor.GetSqlValue(x, context)).ToArray();
}
string sql = rawSql.CommandText;
if (args != null && args.Length > 0)
{
sql = string.Format(sql, args);
}
// 子查询
jf.Append('(');
var cmd = new DbRawCommand(sql, context.Parameters, CommandType.Text);
jf.Append(cmd.CommandText);
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
jf.Append(' ');
}
else
{
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(tree.From);
jf.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
jf.Append(' ');
jf.Append(alias);
jf.Append(' ');
bool isNoLock = ((SqlServerDbContext)context.DbContext).NoLock;
if (isNoLock && !string.IsNullOrEmpty(this._widthNoLock) && !typeRuntime.IsTemporary)
{
jf.Append(this._widthNoLock);
}
}
// LEFT<INNER> JOIN 子句
if (tree.Joins != null)
{
var visitor = new SqlServerJoinExpressionVisitor(ag, jf);
visitor.Visit(tree.Joins);
}
wf.Indent = jf.Indent;
// WHERE 子句
if (tree.Wheres != null)
{
var visitor = new WhereExpressionVisitor(ag, wf);
visitor.Visit(tree.Wheres);
result.AddNavMembers(visitor.NavMembers);
}
// GROUP BY 子句
if (tree.GroupBy != null)
{
var visitor = new GroupByExpressionVisitor(ag, wf);
visitor.Visit(tree.GroupBy);
result.AddNavMembers(visitor.NavMembers);
}
// HAVING 子句
if (tree.Havings != null)
{
var visitor = new HavingExpressionVisitor(ag, wf, tree.GroupBy);
visitor.Visit(tree.Havings);
result.AddNavMembers(visitor.NavMembers);
}
// ORDER 子句
if (tree.OrderBys != null && tree.OrderBys.Count > 0 && useOrderBy)
{
var visitor = new OrderByExpressionVisitor(ag, wf, tree.GroupBy, null);
visitor.Visit(tree.OrderBys);
result.AddNavMembers(visitor.NavMembers);
}
#endregion
#region 分页查询
if (tree.Skip > 0)
{
if (tree.OrderBys == null || tree.OrderBys.Count == 0)
{
throw new XFrameworkException("The method 'OrderBy' must be called before 'Skip'.");
}
wf.AppendNewLine();
wf.Append("OFFSET ");
wf.Append(this.Constor.GetSqlValue(tree.Skip, context));
wf.Append(" ROWS");
if (tree.Take > 0)
{
wf.Append(" FETCH NEXT ");
wf.Append(this.Constor.GetSqlValue(tree.Take, context));
wf.Append(" ROWS ONLY ");
}
}
#endregion 分页查询
#region 嵌套查询
if (useAggregate && useSubquery)
{
result.CombineFragments();
indent -= 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias);
jf.Append(' ');
}
#endregion 嵌套查询
#region 嵌套导航
if (tree.SelectHasMany && subquery.Aggregate == null &&
subquery != null && subquery.OrderBys != null && subquery.OrderBys.Count > 0 && !(subquery.Skip > 0 || subquery.Take > 0))
{
// TODO Include 从表，没分页，OrderBy 报错
result.CombineFragments();
var visitor = new OrderByExpressionVisitor(ag, jf, null, null);
visitor.Visit(subquery.OrderBys);
}
#endregion 嵌套导航
#region 并集查询
// UNION 子句
if (tree.Unions != null && tree.Unions.Count > 0)
{
result.CombineFragments();
for (int index = 0; index < tree.Unions.Count; index++)
{
jf.AppendNewLine();
jf.Append("UNION ALL");
if (indent == 0)
{
jf.AppendNewLine();
}
DbRawCommand cmd = this.TranslateSelectCommand(tree.Unions[index], indent, isOutermost, context);
jf.Append(cmd.CommandText);
}
}
#endregion 并集查询
#region Any 子句
// 'Any' 子句
if (tree.HasAny)
{
result.CombineFragments();
indent -= 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append(") SELECT 1 ELSE SELECT 0");
}
#endregion Any 子句
#region 还原状态
context.CurrentExpressionType = srcDbExpressionType;
context.CurrentIsOutermost = srcIsOutermost;
#endregion
return(result);
}
