public static ExprList ConvertMerge(ExprMerge merge, string tempTableName)
{
var derivedTableValues = merge.Source as ExprDerivedTableValues;
if (derivedTableValues == null)
{
throw new SqExpressException("Only derived table values can be used as a source in MERGE simulation");
}
var acc = new List <IExprExec>();
var keys = ExtractKeys(merge, derivedTableValues.Alias.Alias);
var exprInsertIntoTmp = TempTableData.FromDerivedTableValuesInsert(derivedTableValues, keys.SourceKeys, out var tempTable, name: tempTableName, alias: Alias.From(derivedTableValues.Alias.Alias));
acc.AddRange(exprInsertIntoTmp.Expressions);
//MATCHED
var e = WhenMatched(merge, tempTable);
if (e != null)
{
acc.Add(e);
}
//NOT MATCHED BY TARGET
e = WhenNotMatchedByTarget(merge, tempTable, keys);
if (e != null)
{
acc.Add(e);
}
//NOT MATCHED BY SOURCE
e = WhenNotMatchedBySource(merge, tempTable);
if (e != null)
{
acc.Add(e);
}
acc.Add(new ExprStatement(tempTable.Script.Drop()));
return(new ExprList(acc));
}
public static TempTableData FromDerivedTableValues(ExprDerivedTableValues derivedTableValues, IReadOnlyList <ExprColumnName>?keys, Alias alias = default, string?name = null)
{
var result = new TempTableData(string.IsNullOrEmpty(name) || name == null ? GenerateName() : name, alias);
derivedTableValues.Columns.AssertNotEmpty("Columns list cannot be empty");
derivedTableValues.Values.Items.AssertNotEmpty("Rows list cannot be empty");
TableColumn?[] tableColumns = new TableColumn?[derivedTableValues.Columns.Count];
for (var rowIndex = 0; rowIndex < derivedTableValues.Values.Items.Count; rowIndex++)
{
var lastRow = rowIndex + 1 == derivedTableValues.Values.Items.Count;
var row = derivedTableValues.Values.Items[rowIndex];
if (row.Items.Count != derivedTableValues.Columns.Count)
{
throw new SqExpressException("Number of values in a row does not match number of columns");
}
for (var valueIndex = 0; valueIndex < row.Items.Count; valueIndex++)
{
var value = row.Items[valueIndex];
var previousColumn = tableColumns[valueIndex];
var currentColumnName = derivedTableValues.Columns[valueIndex];
var res = value.Accept(ExprValueTypeAnalyzer <TableColumn?, TempTableBuilderCtx> .Instance,
new ExprValueTypeAnalyzerCtx <TableColumn?, TempTableBuilderCtx>(
new TempTableBuilderCtx(
currentColumnName,
previousColumn,
CheckIsPk(currentColumnName)),
result));
tableColumns[valueIndex] = res;
if (lastRow)
{
if (ReferenceEquals(res, null))
{
throw new SqExpressException($"Could not evaluate column type at {valueIndex}");
}
}
}
}
result.AddColumns(tableColumns !);
return(result);
bool CheckIsPk(ExprColumnName columnName)
{
if (keys == null || keys.Count < 1)
{
return(false);
}
for (var index = 0; index < keys.Count; index++)
{
var key = keys[index];
if (key.LowerInvariantName == columnName.LowerInvariantName)
{
return(true);
}
}
return(false);
}
}
