sql-server - 将数据类型 bigint 转换为 varchar 时出错。

Question

DECLARE @ID BIGINT
set @ID = 1323
UPDATE School 
SET RegistrationFee = 'fee_' + @ID --<<<<error 
Where SchoolRegistrationId = 123

将数据类型 varchar 转换为 bigint 时出错。

Answer 1

您需要将 bigint 显式转换为 varchar:

DECLARE @ID BIGINT
set @ID = 1323

UPDATE School 
SET RegistrationFee = 'fee_' + CAST(@ID AS VARCHAR(15)) 
WHERE SchoolRegistrationId = 123

T-SQL 不会自动为您执行此操作 - 您需要明确且清楚地了解它。