public static Field GetField(this ValueExpression valueExpression, string columnName, ILogger logger, SchemaFile file)
{
if (valueExpression is Literal literal)
{
return(literal.GetField(columnName, logger, file));
}
if (valueExpression is VariableReference variableReference)
{
var variable = file
.FileContext
.Variables
.SelectMany(x => x)
.Distinct(new KeyEqualityComparer <Field, string>(x => x.Name))
.FirstOrDefault(x => x.Name.Equals(variableReference.Name, StringComparison.InvariantCultureIgnoreCase));
if (variable == null)
{
logger.Log(LogLevel.Error, $"Variable is not defined. Fragment: {variableReference.GetTokenText()}");
}
return(variable?.Copy(columnName) ?? new UnknownField()
{
Name = columnName
});
}
if (valueExpression is GlobalVariableExpression globalVariableExpression)
{
switch (globalVariableExpression.Name.ToUpper())
{
case "@@ROWCOUNT":
case "@@CURSOR_ROWS":
case "@@ERROR": // TODO : verify this is the case
case "@@PROCID":
case "@@TIMETICKS":
case "@@CPU_BUSY":
case "@@IO_BUSY":
case "@@IDLE":
case "@@PACK_RECEIVED":
case "@@PACK_SENT":
case "@@CONNECTIONS":
case "@@PACKET_ERRORS":
case "@@TOTAL_READ":
case "@@TOTAL_WRITE":
case "@@TOTAL_ERRORS":
return(new DefaultField()
{
Name = columnName,
Type = FieldType.Int,
Origin = OriginType.GlobalVariable,
IsNullable = false,
});
case "SCOPE_IDENTITY":
case "@@IDENTITY":
{
// https://docs.microsoft.com/en-us/sql/t-sql/functions/scope-identity-transact-sql
return(new DecimalField()
{
Name = columnName,
Type = FieldType.Decimal,
Origin = OriginType.GlobalVariable,
IsNullable = false,
Precision = 38,
Scale = 0,
});
}
case "@@SERVERNAME":
return(new StringField()
{
Name = columnName,
Type = FieldType.String, // nvarchar
Origin = OriginType.GlobalVariable,
IsNullable = false,
Length = 15,
});
case "@@SPID":
return(new DefaultField()
{
Name = columnName,
Type = FieldType.SmallInt,
Origin = OriginType.GlobalVariable,
IsNullable = false,
});
case "@@DATEFIRST":
return(new DefaultField()
{
Name = columnName,
Type = FieldType.TinyInt,
Origin = OriginType.GlobalVariable,
IsNullable = false,
});
default:
break;
}
}
logger.Log(LogLevel.Warning,
LogType.NotSupportedYet,
file.Path,
$"\"{valueExpression.GetType()}\" value expression is not supported yet. " +
$"Fragment: \"{valueExpression.GetTokenText()}\"");
return(new UnknownField()
{
Name = columnName
});
}