When using the UNION operator in PostgreSQL, if you encounter an error that reads “ERROR: each UNION query must have the same number of columns“, it’s because there’s a mismatch in the number of columns returned by the queries on either side of the UNION operator.
This error occurs when the number of columns returned by each SELECT statement is different.
The way to fix this is to ensure that both SELECT statements return the same number of columns.
If you get error Msg 4151 “The type of the first argument to NULLIF cannot be the NULL constant because the type of the first argument has to be known” in SQL Server, it’s because you’re passing a null value as the first argument to the NULLIF() function.
To fix this error, make sure you do not pass the null constant as the first argument to the function. Or if you do, then convert it to a specific data type.
Continue readingIf you get warning number 1287 that reads ‘BINARY expr’ is deprecated and will be removed in a future release. Please use CAST instead when running a query in MySQL, it’s because you’re using the BINARY operator.
The BINARY operator is deprecated as of MySQL 8.0.27.
To fix the issue, cast the value to binary using the CAST() function instead.
If you’re getting SQL Server error Msg 241 that reads Conversion failed when converting date and/or time from character string, it’s probably because you’re trying to convert a string to a date/time value, but that particular string can’t be converted to the date/time type specified.
Continue readingHere are five options for dealing with error Msg 8134 “Divide by zero error encountered” in SQL Server.
Continue readingIf you’re getting SQL Server error Msg 529 that reads something like Explicit conversion from data type int to xml is not allowed, it’s probably because you’re trying to perform a data type conversion that’s not permitted.
SQL Server doesn’t allow certain conversions. If you try to perform such a conversion, you’ll get this error.
Continue readingIf you’re getting SQL Server error Msg 8116 with the message Argument data type varchar is invalid for argument 1 of session_context function, it’s because you’re passing the wrong data type to a function – in this case the SESSION_CONTEXT() function.
If you’re getting SQL Server error Msg 8117 with the message Operand data type varchar is invalid for sum operator, it’s because you’re passing the wrong data type to an operator or function.
In this case, the error indicates that we’re passing a string to the SUM() function. The SUM() function does not operate on strings. It only works on numeric types.
The same error (Msg 8117) can also occur in other contexts – it’s not limited to the SUM() function.
If you’re getting SQL Server error Msg 8116 with text that reads Argument data type date is invalid for argument 1 of substring function, it’s because you’re passing the wrong data type to a function – in this case, the SUBSTRING() function.
You could also see the same error (Msg 8116) in many other contexts – it’s not limited to the SUBSTRING() function.
If you’re getting SQL Server error Msg 8114 that reads something like Error converting data type varchar to numeric, it’s probably because you’re trying to perform a data type conversion that fails due to the value not being able to be converted to the destination type.
It’s not because you can’t convert that type to the new type. It’s because of the value itself.
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