public override SqlInfo[] ConvertToSql(Expression?expression, int level, ConvertFlags flags)
{
expression = SequenceHelper.CorrectExpression(expression, this, Context);
var indexes = SubQuery
.ConvertToIndex(expression, level, flags)
.ToArray();
var result = indexes
.Select(idx => new SqlInfo(idx.MemberChain, idx.Index < 0 ? idx.Sql : SubQuery.SelectQuery.Select.Columns[idx.Index], idx.Index))
.ToArray();
return(result);
}
public override SqlInfo[] ConvertToSql(Expression?expression, int level, ConvertFlags flags)
{
expression = SequenceHelper.CorrectExpression(expression, this, SubQuery);
return(SubQuery
.ConvertToIndex(expression, level, flags)
.Select(info =>
{
var expr = (info.Sql is SqlColumn column) ? column.Expression : info.Sql;
var field = RegisterSourceField(expr, expr, info.Index, info.MemberChain.LastOrDefault());
return new SqlInfo(info.MemberChain, field);
})
.ToArray());
}
public override SqlInfo[] ConvertToSql(Expression?expression, int level, ConvertFlags flags)
{
var queryContext = GetQueryContext();
if (queryContext == null)
{
return(base.ConvertToSql(expression, level, flags));
}
var baseInfos = base.ConvertToSql(null, 0, ConvertFlags.All);
if (flags != ConvertFlags.All && _cte.Fields !.Length == 0 && queryContext.SelectQuery.Select.Columns.Count > 0)
{
// it means that queryContext context already has columns and we need all of them. For example for Distinct.
ConvertToSql(null, 0, ConvertFlags.All);
}
expression = SequenceHelper.CorrectExpression(expression, this, queryContext);
var infos = queryContext.ConvertToIndex(expression, level, flags);
var result = infos
.Select(info =>
{
var baseInfo = baseInfos.FirstOrDefault(bi => bi.CompareMembers(info));
var alias = flags == ConvertFlags.Field ? GenerateAlias(expression) : null;
if (alias == null)
{
alias = baseInfo?.MemberChain.LastOrDefault()?.Name ??
info.MemberChain.LastOrDefault()?.Name;
}
var field = RegisterCteField(baseInfo?.Sql, info.Sql, info.Index, alias);
return(new SqlInfo(info.MemberChain, field));
})
.ToArray();
return(result);
}
public override Expression BuildExpression(Expression?expression, int level, bool enforceServerSide)
{
expression = SequenceHelper.CorrectExpression(expression, this, Sequence);
var expr = Sequence.BuildExpression(expression, level, enforceServerSide);
if (!Disabled && expression == null)
{
var q =
from col in SelectQuery.Select.Columns
where !col.CanBeNull
select SelectQuery.Select.Columns.IndexOf(col);
var idx = q.DefaultIfEmpty(-1).First();
if (idx == -1)
{
idx = SelectQuery.Select.Add(new SqlValue((int?)1));
SelectQuery.Select.Columns[idx].RawAlias = "is_empty";
}
var n = ConvertToParentIndex(idx, this);
Expression e = Expression.Call(
ExpressionBuilder.DataReaderParam,
ReflectionHelper.DataReader.IsDBNull,
ExpressionInstances.Int32Array(n));
var defaultValue = DefaultValue ?? new DefaultValueExpression(Builder.MappingSchema, expr.Type);
if (expr.NodeType == ExpressionType.Parameter)
{
var par = (ParameterExpression)expr;
var pidx = Builder.BlockVariables.IndexOf(par);
if (pidx >= 0)
{
var ex = Builder.BlockExpressions[pidx];
if (ex.NodeType == ExpressionType.Assign)
{
var bex = (BinaryExpression)ex;
if (bex.Left == expr)
{
if (bex.Right.NodeType != ExpressionType.Conditional)
{
Builder.BlockExpressions[pidx] =
Expression.Assign(
bex.Left,
Expression.Condition(e, defaultValue, bex.Right));
}
}
}
}
}
expr = Expression.Condition(e, defaultValue, expr);
}
return(expr);
}
public override IBuildContext?GetContext(Expression?expression, int level, BuildInfo buildInfo)
{
expression = SequenceHelper.CorrectExpression(expression, this, Sequence);
return(Sequence.GetContext(expression, level, buildInfo));
}
public override IsExpressionResult IsExpression(Expression?expression, int level, RequestFor requestFlag)
{
expression = SequenceHelper.CorrectExpression(expression, this, Sequence);
return(Sequence.IsExpression(expression, level, requestFlag));
}
public override SqlInfo[] ConvertToIndex(Expression?expression, int level, ConvertFlags flags)
{
expression = SequenceHelper.CorrectExpression(expression, this, Sequence);
return(Sequence.ConvertToIndex(expression, level, flags));
}
