// 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>
/// 解析 SQL 命令
/// <para>
/// 返回的已经解析语义中执行批次用 null 分开
/// </para>
/// </summary>
/// <param name="dbQueryables">查询语句</param>
/// <returns></returns>
public override List <DbRawCommand> Translate(List <object> dbQueryables)
{
bool haveBegin = false;
ITranslateContext context = null;
var sqlList = new List <DbRawCommand>();
for (int i = 0; i < dbQueryables.Count; i++)
{
object obj = dbQueryables[i];
if (obj == null)
{
continue;
}
if (obj is IDbQueryable)
{
DbQueryable dbQuery = (DbQueryable)obj;
dbQuery.Parameterized = true;
if (context == null)
{
context = this.CreateTranslateContext(dbQuery.DbContext);
}
if (context.Parameters == null)
{
context.Parameters = new List <IDbDataParameter>(8);
}
var cmd = dbQuery.Translate(0, true, context);
if (cmd is DbSelectCommand)
{
// 查询单独执行
if (sqlList.Count > 0 && (i - 1) >= 0 && sqlList[sqlList.Count - 1] != null)
{
sqlList.Add(null);
}
sqlList.Add(cmd);
sqlList.Add(null);
context = this.CreateTranslateContext(dbQuery.DbContext);
context.Parameters = new List <IDbDataParameter>(8);
}
else
{
// 增删改
if (!haveBegin)
{
sqlList.Add(new DbRawCommand("BEGIN"));
haveBegin = true;
}
sqlList.Add(cmd);
if (cmd.Parameters != null && cmd.Parameters.Count > 1000)
{
// 1000个参数，就要重新分批
if (haveBegin)
{
sqlList.Add(new DbRawCommand("END;"));
haveBegin = false;
sqlList.Add(null);
}
context = this.CreateTranslateContext(dbQuery.DbContext);
context.Parameters = new List <IDbDataParameter>(8);
}
if (i + 1 < dbQueryables.Count)
{
// 检查下一条是否是选择语句
bool isQuery = false;
if (dbQueryables[i + 1] is IDbQueryable)
{
var tree = ((DbQueryable)dbQueryables[i + 1]).Parse();
isQuery = tree is DbQuerySelectTree;
}
else if ((dbQueryables[i + 1] is string))
{
string sql = dbQueryables[i + 1].ToString();
string method = string.Empty;
if (sql.Length > 6)
{
method = sql.Substring(0, 6).Trim().ToUpper();
}
isQuery = method == "SELECT";
}
else if (dbQueryables[i + 1] is DbRawSql)
{
string sql = ((DbRawSql)dbQueryables[i + 1]).CommandText;
string method = string.Empty;
if (sql.Length > 6)
{
method = sql.Substring(0, 6).Trim().ToUpper();
}
isQuery = method == "SELECT";
}
// 如果下一条是SELECT 语句，则需要结束当前语句块
if (isQuery)
{
if (haveBegin)
{
sqlList.Add(new DbRawCommand("END;"));
haveBegin = false;
sqlList.Add(null);
}
context = this.CreateTranslateContext(dbQuery.DbContext);
context.Parameters = new List <IDbDataParameter>(8);
}
}
}
}
else if (obj is DbRawSql || obj is string)
{
string sql = string.Empty;
if (obj is string)
{
sql = obj.ToString();
}
else
{
DbRawSql rawSql = (DbRawSql)obj;
// 解析参数
object[] args = null;
if (rawSql.Parameters != null)
{
args = rawSql.Parameters.Select(x => this.Constor.GetSqlValue(x, context)).ToArray();
}
sql = rawSql.CommandText;
if (args != null && args.Length > 0)
{
sql = string.Format(sql, args);
}
}
string methodName = string.Empty;
if (sql.Length > 6)
{
methodName = sql.Substring(0, 6).Trim().ToUpper();
}
if (methodName == "SELECT")
{
if (sqlList.Count > 0 && (i - 1) >= 0 && sqlList[sqlList.Count - 1] != null)
{
sqlList.Add(null);
}
}
var cmd = new DbRawCommand(sql, context.Parameters, CommandType.Text);
sqlList.Add(cmd);
if (methodName == "SELECT")
{
sqlList.Add(cmd);
sqlList.Add(null);
context = this.CreateTranslateContext(obj is DbRawSql ? ((DbRawSql)obj).DbContext : null);
context.Parameters = new List <IDbDataParameter>(8);
}
else if (cmd.Parameters != null && cmd.Parameters.Count > 1000)
{
// 1000个参数，就要重新分批
if (haveBegin)
{
sqlList.Add(new DbRawCommand("END;"));
sqlList.Add(null);
haveBegin = false;
}
context = this.CreateTranslateContext(obj is DbRawSql ? ((DbRawSql)obj).DbContext : null);
context.Parameters = new List <IDbDataParameter>(8);
}
}
else
{
if (!haveBegin)
{
sqlList.Add(new DbRawCommand("BEGIN"));
haveBegin = true;
}
// 解析批量插入操作
List <IDbQueryable> bulkList = obj as List <IDbQueryable>;
if (bulkList != null && bulkList.Count > 0)
{
this.TranslateBulk(sqlList, bulkList);
}
}
if (haveBegin && i == dbQueryables.Count - 1)
{
sqlList.Add(new DbRawCommand("END;"));
}
}
return(sqlList);
}
/// <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>
/// 创建 INSRT 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 TranslateInsertCommand <T>(DbQueryInsertTree tree, ITranslateContext context)
{
ISqlBuilder builder = this.CreateSqlBuilder(context);;
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
if (tree.Entity != null)
{
// 如果没有Sequence列，使用 INSERT ALL INTO 语法，否则就一条一条逐行写入~~
// 批量 INSERT，自增列不会自动赋值
object entity = tree.Entity;
ISqlBuilder columnsBuilder = this.CreateSqlBuilder(context);
ISqlBuilder valuesBuilder = this.CreateSqlBuilder(context);
// 指定插入列
var members = typeRuntime.Members;
if (tree.EntityColumns != null && tree.EntityColumns.Count > 0)
{
members = new MemberAccessorCollection();
for (int i = 0; i < tree.EntityColumns.Count; i++)
{
Expression curExpr = tree.EntityColumns[i];
if (curExpr.NodeType == ExpressionType.Lambda)
{
curExpr = (curExpr as LambdaExpression).Body.ReduceUnary();
}
if (curExpr.NodeType != ExpressionType.MemberAccess)
{
throw new XFrameworkException("Can't read field name from expression {0}", tree.EntityColumns[i]);
}
MemberExpression member = curExpr as MemberExpression;
string name = member.Member.Name;
members[name] = typeRuntime.Members[name];
}
}
// 自增列参数
IDbDataParameter seqParameter = null;
// 自增列标记
ColumnAttribute seqColumn = null;
foreach (var item in members)
{
var m = item as FieldAccessorBase;
if (m == null || !m.IsDbField)
{
continue;
}
columnsBuilder.AppendMember(null, m.Member, typeRuntime.Type);
columnsBuilder.Append(',');
if (m == typeRuntime.Identity)
{
seqColumn = m.Column;
if (tree.Bulk == null)
{
// 非批量INSERT，产生一个 OUTPUT 类型的参数
string parameterName = string.Format("{0}{1}{2}", this.ParameterPrefix, AppConst.PARAMETER_NAME_PRIFIX, context.Parameters.Count);
seqParameter = this.DbProvider.CreateParameter(parameterName, -1, direction: ParameterDirection.Output);
context.Parameters.Add(seqParameter);
valuesBuilder.Append(seqParameter.ParameterName);
valuesBuilder.Append(',');
}
else
{
valuesBuilder.AppendMember(((OracleColumnAttribute)m.Column).SEQName);
valuesBuilder.Append(".NEXTVAL");
valuesBuilder.Append(',');
}
}
else
{
var value = m.Invoke(entity);
string sqlExpression = this.Constor.GetSqlValueWidthDefault(value, context, m.Column);
valuesBuilder.Append(sqlExpression);
valuesBuilder.Append(',');
}
}
columnsBuilder.Length -= 1;
valuesBuilder.Length -= 1;
if (tree.Bulk == null)
{
// 非批量INSERT，产生一个 OUTPUT 类型的参数
if (seqParameter != null)
{
seqParameter.Direction = ParameterDirection.Output;
seqParameter.DbType = DbType.Int64;
builder.Append("SELECT ");
builder.AppendMember(((OracleColumnAttribute)seqColumn).SEQName);
builder.Append(".NEXTVAL INTO ");
builder.Append(seqParameter.ParameterName);
builder.Append(" FROM DUAL;");
builder.AppendNewLine();
//useSEQ = true;
}
builder.Append("INSERT ");
}
else
{
// 批量 INSERT
if (!tree.Bulk.OnlyValue || seqColumn != null)
{
builder.Append("INSERT ");
}
// 如果有自增列则不使用 INSERT ALL INTO 语法
if (!tree.Bulk.OnlyValue && seqColumn == null)
{
builder.Append("ALL ");
}
}
builder.Append("INTO ");
builder.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
builder.Append('(');
builder.Append(columnsBuilder);
builder.Append(')');
builder.AppendNewLine();
builder.AppendTab();
builder.Append("VALUES");
builder.Append('(');
builder.Append(valuesBuilder);
builder.Append(')');
if (tree.Bulk == null)
{
builder.Append(';');
}
else
{
if (seqColumn != null)
{
if (tree.Bulk.IsEndPos)
{
builder.Append(";");
}
else
{
builder.AppendNewLine(";");
}
}
else
{
builder.AppendNewLine();
if (tree.Bulk.IsEndPos)
{
builder.Append("SELECT 1 FROM DUAL;");
}
}
}
}
else if (tree.Select != null)
{
builder.Append("INSERT INTO ");
builder.AppendTable(typeRuntime.TableSchema, typeRuntime.TableName, typeRuntime.IsTemporary);
builder.Append('(');
var srcExpressionType = context.CurrentExpressionType;
var srcIsOutermost = context.CurrentIsOutermost;
context.CurrentExpressionType = DbExpressionType.Insert;
context.CurrentIsOutermost = false;
var cmd = this.TranslateSelectCommand(tree.Select, 0, false, context) as DbSelectCommand;
context.CurrentExpressionType = srcExpressionType;
context.CurrentIsOutermost = srcIsOutermost;
int index = 0;
foreach (var column in cmd.SelectedColumns)
{
builder.AppendMember(column.Name);
if (index < cmd.SelectedColumns.Count - 1)
{
builder.Append(',');
}
index++;
}
builder.Append(')');
builder.AppendNewLine();
builder.Append(cmd.CommandText);
builder.Append(';');
}
var result = new DbRawCommand(builder.ToString(), builder.TranslateContext != null ? builder.TranslateContext.Parameters : null, System.Data.CommandType.Text);
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);
}
