protected virtual void VisitStringLiteralExpression(StringBuilder sb, BinaryStringOperator binaryStringOperator,
LiteralExpression <string> expression)
{
if (string.IsNullOrEmpty(expression.Value))
{
sb.Append(" NULL ");
return;
}
string v;
switch (binaryStringOperator)
{
case BinaryStringOperator.StartsWith:
v = expression.Value + "%";
break;
case BinaryStringOperator.EndsWith:
v = "%" + expression.Value;
break;
case BinaryStringOperator.Contains:
v = "%" + expression.Value + "%";
break;
case BinaryStringOperator.Equals:
case BinaryStringOperator.NotEquals:
default:
v = expression.Value;
break;
}
sb.Append(CreateParameter(v).ParameterName);
}
protected virtual string GetBinaryStringExpressionString(BinaryStringOperator binaryStringOperator,
Expression right)
{
if (right is LiteralExpression &&
(Equals(null, ((LiteralExpression)right).Value) ||
Equals(string.Empty, ((LiteralExpression)right).Value)))
{
switch (binaryStringOperator)
{
case BinaryStringOperator.Equals:
return(" IS ");
case BinaryStringOperator.NotEquals:
return(" IS NOT ");
case BinaryStringOperator.Contains:
case BinaryStringOperator.EndsWith:
case BinaryStringOperator.StartsWith:
default:
break;
}
}
switch (binaryStringOperator)
{
case BinaryStringOperator.Equals:
return(" = ");
case BinaryStringOperator.NotEquals:
return(" <> ");
case BinaryStringOperator.Contains:
case BinaryStringOperator.EndsWith:
case BinaryStringOperator.StartsWith:
default:
return(" LIKE ");
}
}