/// <summary>
/// 创建 DELETE 命令
/// </summary>
/// <param name="dbQuery">查询语义</param>
/// <param name="token">解析上下文</param>
/// <returns></returns>
protected override RawCommand ResolveDeleteCommand <T>(IDbQueryableInfo_Delete dbQuery, ResolveToken token)
{
var context = (SqlServerDbContext)token.DbContext;
ISqlBuilder builder = this.CreateSqlBuilder(token);
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
builder.Append("DELETE t0 FROM ");
builder.AppendMember(typeRuntime.TableName, !typeRuntime.IsTemporary);
builder.Append(" t0 ");
if (dbQuery.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 = dbQuery.Entity;
builder.AppendNewLine();
builder.Append("WHERE ");
foreach (var m in typeRuntime.KeyMembers)
{
var column = m.Column;
var value = m.Invoke(entity);
var seg = this.DbValue.GetSqlValue(value, token, column);
builder.AppendMember("t0", m.Member.Name);
builder.Append(" = ");
builder.Append(seg);
builder.Append(" AND ");
}
builder.Length -= 5;
}
else if (dbQuery.Query != null)
{
TableAlias aliases = this.PrepareTableAlias(dbQuery.Query, token);
var cmd = new SqlServerMappingCommand(context, aliases, token)
{
HasMany = dbQuery.Query.HasMany
};
ExpressionVisitorBase visitor = new SqlServerJoinExpressionVisitor(context, aliases, dbQuery.Query.Joins);
visitor.Write(cmd.JoinFragment);
visitor = new WhereExpressionVisitor(this, aliases, dbQuery.Query.Where);
visitor.Write(cmd.WhereFragment);
cmd.AddNavMembers(visitor.NavMembers);
builder.Append(cmd.CommandText);
}
return(new RawCommand(builder.ToString(), builder.Token != null ? builder.Token.Parameters : null, System.Data.CommandType.Text));
}
/// <summary>
/// 创建 UPDATE 命令
/// </summary>
/// <param name="dbQuery">查询语义</param>
/// <param name="token">解析上下文</param>
/// <returns></returns>
protected override RawCommand ResolveUpdateCommand <T>(IDbQueryableInfo_Update dbQuery, ResolveToken token)
{
var context = (SqlServerDbContext)token.DbContext;
ISqlBuilder builder = this.CreateSqlBuilder(token);
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo <T>();
builder.Append("UPDATE t0 SET");
builder.AppendNewLine();
if (dbQuery.Entity != null)
{
object entity = dbQuery.Entity;
ISqlBuilder seg_Where = this.CreateSqlBuilder(token);
bool useKey = false;
int length = 0;
foreach (var m in typeRuntime.Members)
{
var column = m.Column;
if (column != null && column.IsIdentity)
{
goto gotoLabel; // Fix issue# 自增列同时又是主键
}
if (column != null && column.NoMapped)
{
continue;
}
if (m.Column != null && column.DbType is SqlDbType && (SqlDbType)column.DbType == SqlDbType.Timestamp)
{
continue; // 行版本号
}
if (m.ForeignKey != null)
{
continue;
}
if (m.Member.MemberType == System.Reflection.MemberTypes.Method)
{
continue;
}
builder.AppendMember("t0", m.Member.Name);
builder.Append(" = ");
gotoLabel:
var value = m.Invoke(entity);
var seg = this.DbValue.GetSqlValueWidthDefault(value, token, column);
if (column == null || !column.IsIdentity)
{
builder.Append(seg);
length = builder.Length;
builder.Append(',');
builder.AppendNewLine();
}
if (column != null && column.IsKey)
{
useKey = true;
seg_Where.AppendMember("t0", m.Member.Name);
seg_Where.Append(" = ");
seg_Where.Append(seg);
seg_Where.Append(" AND ");
}
}
if (!useKey)
{
throw new XFrameworkException("Update<T>(T value) require entity must have key column.");
}
builder.Length = length;
seg_Where.Length -= 5;
builder.AppendNewLine();
builder.Append("FROM ");
builder.AppendMember(typeRuntime.TableName, !typeRuntime.IsTemporary);
builder.Append(" t0");
builder.AppendNewLine();
builder.Append("WHERE ");
builder.Append(seg_Where);
}
else if (dbQuery.Expression != null)
{
TableAlias aliases = this.PrepareTableAlias(dbQuery.Query, token);
ExpressionVisitorBase visitor = null;
visitor = new UpdateExpressionVisitor(this, aliases, dbQuery.Expression);
visitor.Write(builder);
builder.AppendNewLine();
builder.Append("FROM ");
builder.AppendMember(typeRuntime.TableName, !typeRuntime.IsTemporary);
builder.AppendAs("t0");
var cmd = new SqlServerMappingCommand(context, aliases, token)
{
HasMany = dbQuery.Query.HasMany
};
visitor = new SqlServerJoinExpressionVisitor(context, aliases, dbQuery.Query.Joins);
visitor.Write(cmd.JoinFragment);
visitor = new WhereExpressionVisitor(this, aliases, dbQuery.Query.Where);
visitor.Write(cmd.WhereFragment);
cmd.AddNavMembers(visitor.NavMembers);
builder.Append(cmd.CommandText);
}
return(new RawCommand(builder.ToString(), builder.Token != null ? builder.Token.Parameters : null, System.Data.CommandType.Text));
}
/// <summary>
/// 解析 SELECT 命令
/// </summary>
/// <param name="dbQuery">查询语义</param>
/// <param name="indent">缩进</param>
/// <param name="isOuter">指示是最外层查询</param>
/// <param name="token">解析上下文</param>
/// <returns></returns>
protected override RawCommand ResolveSelectCommand(IDbQueryableInfo_Select dbQuery, int indent, bool isOuter, ResolveToken token)
{
// 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 = dbQuery.Subquery as IDbQueryableInfo_Select;
if (dbQuery.HasMany && subQuery != null && subQuery.Aggregate != null)
{
dbQuery = subQuery;
}
bool useStatis = dbQuery.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
string alias0 = token != null && !string.IsNullOrEmpty(token.AliasPrefix) ? (token.AliasPrefix + "0") : "t0";
bool useSubQuery = dbQuery.HasDistinct || dbQuery.GroupBy != null || dbQuery.Skip > 0 || dbQuery.Take > 0;
bool useOrderBy = (!useStatis || dbQuery.Skip > 0) && !dbQuery.HasAny && (!dbQuery.IsParsedByMany || (dbQuery.Skip > 0 || dbQuery.Take > 0));
var context = (SqlServerDbContext)token.DbContext;
TableAlias aliases = this.PrepareTableAlias(dbQuery, token);
var result = new SqlServerMappingCommand(context, aliases, token)
{
HasMany = dbQuery.HasMany
};
ISqlBuilder jf = result.JoinFragment;
ISqlBuilder wf = result.WhereFragment;
jf.Indent = indent;
#region 嵌套查询
if (useStatis && useSubQuery)
{
// SELECT
jf.Append("SELECT ");
jf.AppendNewLine();
// SELECT COUNT(1)
var visitor_ = new AggregateExpressionVisitor(this, aliases, dbQuery.Aggregate, dbQuery.GroupBy, alias0);
visitor_.Write(jf);
result.AddNavMembers(visitor_.NavMembers);
// SELECT COUNT(1) FROM
jf.AppendNewLine();
jf.Append("FROM ( ");
indent += 1;
jf.Indent = indent;
}
#endregion 嵌套查询
#region 择子句
// SELECT 子句
if (jf.Indent > 0)
{
jf.AppendNewLine();
}
if (dbQuery.HasAny)
{
jf.Append("IF EXISTS(");
indent += 1;
jf.Indent = indent;
jf.AppendNewLine();
}
jf.Append("SELECT ");
if (useStatis && !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(this, aliases, dbQuery.Aggregate, dbQuery.GroupBy);
visitor_.Write(jf);
result.AddNavMembers(visitor_.NavMembers);
}
else
{
// DISTINCT 子句
if (dbQuery.HasDistinct)
{
jf.Append("DISTINCT ");
}
// TOP 子句
if (dbQuery.Take > 0 && dbQuery.Skip == 0)
{
jf.AppendFormat("TOP({0})", this.DbValue.GetSqlValue(dbQuery.Take, token));
}
// Any
if (dbQuery.HasAny)
{
jf.Append("TOP 1 1");
}
#region 字段
if (!dbQuery.HasAny)
{
// SELECT 范围
var visitor_ = new ColumnExpressionVisitor(this, aliases, dbQuery);
visitor_.Write(jf);
result.PickColumns = visitor_.PickColumns;
result.PickColumnText = visitor_.PickColumnText;
result.PickNavDescriptors = visitor_.PickNavDescriptors;
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 (dbQuery.Subquery != null)
{
// 子查询
jf.Append('(');
RawCommand cmd = this.ResolveSelectCommand(dbQuery.Subquery, indent + 1, false, token);
jf.Append(cmd.CommandText);
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias0);
jf.Append(' ');
}
else
{
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(dbQuery.FromType);
jf.AppendMember(typeRuntime.TableName, !typeRuntime.IsTemporary);
jf.Append(' ');
jf.Append(alias0);
jf.Append(' ');
if (context.NoLock && !string.IsNullOrEmpty(this._widthNoLock))
{
jf.Append(this._widthNoLock);
}
}
// LEFT<INNER> JOIN 子句
ExpressionVisitorBase visitor = new SqlServerJoinExpressionVisitor(context, aliases, dbQuery.Joins);
visitor.Write(jf);
wf.Indent = jf.Indent;
// WHERE 子句
visitor = new WhereExpressionVisitor(this, aliases, dbQuery.Where);
visitor.Write(wf);
result.AddNavMembers(visitor.NavMembers);
// GROUP BY 子句
visitor = new GroupByExpressionVisitor(this, aliases, dbQuery.GroupBy);
visitor.Write(wf);
result.AddNavMembers(visitor.NavMembers);
// HAVING 子句
visitor = new HavingExpressionVisitor(this, aliases, dbQuery.Having, dbQuery.GroupBy);
visitor.Write(wf);
result.AddNavMembers(visitor.NavMembers);
// ORDER 子句
if (dbQuery.OrderBys.Count > 0 && useOrderBy)
{
visitor = new OrderByExpressionVisitor(this, aliases, dbQuery.OrderBys, dbQuery.GroupBy);
visitor.Write(wf);
result.AddNavMembers(visitor.NavMembers);
}
#endregion 顺序解析
#region 分页查询
if (dbQuery.Skip > 0)
{
if (dbQuery.OrderBys.Count == 0)
{
throw new XFrameworkException("The method 'OrderBy' must be called before 'Skip'.");
}
wf.AppendNewLine();
wf.Append("OFFSET ");
wf.Append(this.DbValue.GetSqlValue(dbQuery.Skip, token));
wf.Append(" ROWS");
if (dbQuery.Take > 0)
{
wf.Append(" FETCH NEXT ");
wf.Append(this.DbValue.GetSqlValue(dbQuery.Take, token));
wf.Append(" ROWS ONLY ");
}
}
#endregion 分页查询
#region 嵌套查询
if (useStatis && useSubQuery)
{
result.CombineFragments();
indent -= 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append(") ");
jf.Append(alias0);
jf.Append(' ');
}
#endregion 嵌套查询
#region 嵌套导航
if (dbQuery.HasMany && subQuery.Aggregate == null && subQuery != null && subQuery.OrderBys.Count > 0 && !(subQuery.Skip > 0 || subQuery.Take > 0))
{
// TODO Include 从表，没分页，OrderBy 报错
result.CombineFragments();
visitor = new OrderByExpressionVisitor(this, aliases, subQuery.OrderBys);
visitor.Write(jf);
}
#endregion 嵌套导航
#region 并集查询
// UNION 子句
if (dbQuery.Unions != null && dbQuery.Unions.Count > 0)
{
result.CombineFragments();
for (int index = 0; index < dbQuery.Unions.Count; index++)
{
jf.AppendNewLine();
jf.Append("UNION ALL");
if (indent == 0)
{
jf.AppendNewLine();
}
RawCommand cmd = this.ResolveSelectCommand(dbQuery.Unions[index], indent, isOuter, token);
jf.Append(cmd.CommandText);
}
}
#endregion 并集查询
#region Any 子句
// 'Any' 子句
if (dbQuery.HasAny)
{
result.CombineFragments();
indent -= 1;
jf.Indent = indent;
jf.AppendNewLine();
jf.Append(") SELECT 1 ELSE SELECT 0");
}
#endregion Any 子句
return(result);
}
