public void NaturalInnerJoin()
{
SqlExpression expression = null;
Assert.DoesNotThrow(() => expression = SqlExpression.Parse("SELECT * FROM persons, codes"));
Assert.IsNotNull(expression);
Assert.IsInstanceOf <SqlQueryExpression>(expression);
SqlExpression resultExpression = null;
Assert.DoesNotThrow(() => resultExpression = expression.Evaluate(Query, null));
Assert.IsNotNull(resultExpression);
Assert.IsInstanceOf <SqlConstantExpression>(resultExpression);
var constantExpression = (SqlConstantExpression)resultExpression;
Assert.IsInstanceOf <QueryType>(constantExpression.Value.Type);
var queryPlan = ((SqlQueryObject)constantExpression.Value.Value);
ITable result = null;
Assert.DoesNotThrow(() => result = queryPlan.QueryPlan.Evaluate(Query));
Assert.IsNotNull(result);
}
public void SetValue(IQuery context, SqlExpression expression)
{
if (expression == null)
{
throw new ArgumentNullException("expression");
}
if (IsConstant)
{
throw new InvalidOperationException();
}
if (!expression.IsConstant())
{
throw new ArgumentException();
}
Expression = expression;
var exp = expression.Evaluate(context, null);
if (exp.ExpressionType != SqlExpressionType.Constant)
{
throw new InvalidOperationException();
}
var value = ((SqlConstantExpression)exp).Value;
SetValue(value);
}
private Field Evaluate(SqlExpression expression, IRequest queryContext)
{
var ignoreCase = queryContext.Query.IgnoreIdentifiersCase();
// Resolve any variables to the table_def for this expression.
expression = Table.TableInfo.ResolveColumns(ignoreCase, expression);
// Get the variable resolver and evaluate over this data.
IVariableResolver vresolver = VariableResolver;
var reduced = expression.Evaluate(queryContext, vresolver, null);
if (reduced.ExpressionType != SqlExpressionType.Constant)
{
throw new InvalidOperationException("The DEFAULT expression of the column cannot be reduced to a constant");
}
return(((SqlConstantExpression)reduced).Value);
}
