Operand shoshould contain 1 column (s), operandcontain

Operand shoshould contain 1 column (s), operandcontain

This error was found during the SQL test today: Operand shoshould contain 1 column (s ).

The reason is that there are multiple fields behind the in condition, and there can only be one field behind the in condition.

SQL statement error, prompt: "#1241-Operand shoshould contain 1 column (s)" error

The subquery in the right brace of the IN predicate can only output one field, but your subquery uses the symbol "*". IN this way, the database engine will output all fields IN the es_message table to the brackets on the right of the IN, and of course an error will be reported.

Correction Method: Specify only one field to be compared after the SELECT statement of the subquery.

SQL statement error: Prompt: "#1241-Operand shoshould contain 1 column (s)" error

SELECT * FROM ies_message where msgsendtype = 2
Which columns are queried,
Msgsendtype IN can be followed by only one column.