/// <summary>
/// Checks if a when expression is set within the MERGE-statement and resolves it if so
/// </summary>
private void ResolveWhenExpression(ReadOnlySpan <TSQLToken> tokens, ref int fileIndex, CompilerContext context)
{
if (!tokens[fileIndex].Text.Equals("when", StringComparison.InvariantCultureIgnoreCase))
{
return;
}
else
{
fileIndex++; //skip 'when'
}
if (tokens[fileIndex].Text.Equals("matched", StringComparison.InvariantCultureIgnoreCase))
{
fileIndex++; //skip 'matched'
if (tokens[fileIndex].Text.Equals("and", StringComparison.InvariantCultureIgnoreCase))
{
fileIndex++; //skip 'and'
SearchConditionResolver.Resolve(tokens, ref fileIndex, context);
}
if (!tokens[fileIndex].Text.Equals("then", StringComparison.InvariantCultureIgnoreCase))
{
throw new InvalidSqlException("WHEN-expression does not contain the THEN-Keyword");
}
else
{
fileIndex++; //skip 'then'
ResolveMergeMatched(tokens, ref fileIndex, context);
}
}
else if (tokens[fileIndex].Text.Equals("not", StringComparison.InvariantCultureIgnoreCase))
{
fileIndex += 2; //skip 'not matched'
if (tokens[fileIndex].Text.Equals("by", StringComparison.InvariantCultureIgnoreCase))
{
fileIndex++; //skip 'by'
if (tokens[fileIndex].Text.Equals("source", StringComparison.InvariantCultureIgnoreCase))
{
fileIndex++; //skip source
if (tokens[fileIndex].Text.Equals("and", StringComparison.InvariantCultureIgnoreCase))
{
fileIndex++; //skip 'and'
SearchConditionResolver.Resolve(tokens, ref fileIndex, context);
}
if (!tokens[fileIndex].Text.Equals("then", StringComparison.InvariantCultureIgnoreCase))
{
throw new InvalidSqlException("WHEN-expression does not contain the THEN-Keyword");
}
else
{
fileIndex++; //skip 'then'
ResolveMergeMatched(tokens, ref fileIndex, context);
}
return;
}
if (tokens[fileIndex].Text.Equals("target", StringComparison.InvariantCultureIgnoreCase))
{
fileIndex++;
}
}
if (tokens[fileIndex].Text.Equals("and", StringComparison.InvariantCultureIgnoreCase))
{
fileIndex++; //skip 'and'
SearchConditionResolver.Resolve(tokens, ref fileIndex, context);
}
if (!tokens[fileIndex].Text.Equals("then", StringComparison.InvariantCultureIgnoreCase))
{
throw new InvalidSqlException("WHEN-expression does not contain the THEN-Keyword");
}
else
{
fileIndex++; //skip 'then'
ResolveMergeNotMatched(tokens, ref fileIndex, context);
}
}
else
{
throw new InvalidSqlException("Invalid WHEN-expression within MERGE-statement");
}
}
public DataManipulation Resolve(ReadOnlySpan <TSQLToken> tokens, ref int fileIndex, CompilerContext context)
{
manipulation = new DataManipulation();
fileIndex++; //skip "merge"
//skip top expression
SkipTopExpression(tokens, ref fileIndex, context);
if (tokens[fileIndex].Text.ToLower().Equals("into"))
{
fileIndex++;
}
targetObject = StatementResolveHelper.ResolveDatabaseObject(tokens, ref fileIndex, context);
context.AddDatabaseObjectToCurrentContext(targetObject);
if (!tokens[fileIndex].Text.ToLower().Equals("using"))
{
throw new InvalidSqlException("Trying to resolve a merge-statement without using keyword");
}
var source = ResolveUsingStatement(tokens, ref fileIndex, context);
context.AddDatabaseObjectToCurrentContext(source);
if (!tokens[fileIndex].Text.Equals("on", StringComparison.InvariantCultureIgnoreCase))
{
throw new InvalidSqlException("Expected 'ON' keyword when resolving a 'MERGE'-statement");
}
fileIndex++; //skip 'on'
SearchConditionResolver.Resolve(tokens, ref fileIndex, context);
while (tokens[fileIndex].Text.Equals("when", StringComparison.InvariantCultureIgnoreCase))
{
ResolveWhenExpression(tokens, ref fileIndex, context);
}
var beautified = new List <Expression>();
foreach (var exp in manipulation.Expressions)
{
beautified.Add(Beautifier.BeautifyColumns(exp, context));
}
manipulation.Expressions = beautified;
while (!tokens[fileIndex].Text.ToLower().Equals(";"))
{
fileIndex++;
if (fileIndex == tokens.Length)
{
throw new InvalidSqlException("Trying to resolve a merge-statement without proper ';' determination");
}
}
fileIndex++; //skip ';'
context.CurrentDatabaseObjectContext.Pop();
return(manipulation);
}
public Expression Resolve(ReadOnlySpan <TSQLToken> tokens, ref int fileIndex, CompilerContext context)
{
List <Expression> expressions = new List <Expression>();
// The CASE expression has two formats: 'simple' and 'searched'. For more information visit:
// https://docs.microsoft.com/en-us/sql/t-sql/language-elements/case-transact-sql?view=sql-server-2017
bool isSimpleFormat = false;
fileIndex++; //skip "case"
if (!tokens[fileIndex].Text.ToLower().Equals("when"))
{
isSimpleFormat = true;
StatementResolveHelper.ResolveExpression(tokens, ref fileIndex, context);
}
do
{
fileIndex++; //skip 'when'
if (isSimpleFormat)
{
StatementResolveHelper.ResolveExpression(tokens, ref fileIndex, context);
}
else
{
SearchConditionResolver.Resolve(tokens, ref fileIndex, context);
}
fileIndex++; //skip 'then'
Expression thenExpression = StatementResolveHelper.ResolveExpression(tokens, ref fileIndex, context);
if (thenExpression.Type.Equals(ExpressionType.COLUMN))
{
expressions.Add(thenExpression);
}
else if (thenExpression.Type.Equals(ExpressionType.COMPLEX) || thenExpression.Type.Equals(ExpressionType.SCALAR_FUNCTION))
{
expressions.AddRange(thenExpression.ChildExpressions);
}
if (tokens.Length <= fileIndex)
{
throw new InvalidSqlException("Trying to resolve case-statement without 'end'-keyword");
}
if (tokens[fileIndex].Text.ToLower().Equals("when"))
{
continue;
}
if (tokens[fileIndex].Text.ToLower().Equals("else"))
{
fileIndex++; //skip 'else'
Expression elseExpression = StatementResolveHelper.ResolveExpression(tokens, ref fileIndex, context);
if (elseExpression.Type.Equals(ExpressionType.COLUMN))
{
expressions.Add(elseExpression);
}
else if (elseExpression.Type.Equals(ExpressionType.COMPLEX) || elseExpression.Type.Equals(ExpressionType.SCALAR_FUNCTION))
{
expressions.AddRange(elseExpression.ChildExpressions);
}
}
if (tokens[fileIndex].Text.ToLower().Equals("end"))
{
fileIndex++; //skip 'end'
break;
}
} while (true);
if (expressions.Count == 1)
{
return(expressions[0]);
}
else
{
return(new Expression(ExpressionType.SCALAR_FUNCTION)
{
Name = "CASE",
ChildExpressions = expressions
});
}
}
