Question

我已尝试过以下代码的多种不同组合，但我不断收到同样的错误。

我之前发现的解决方案such as this one，没有嵌入动态SQL的额外复杂性。任何帮助将不胜感激。

代码：

DECLARE @table as NVARCHAR(25) = 'proposals'
DECLARE @column as NVARCHAR(25) = 'daypart'
DECLARE @modulo as NVARCHAR(5) = ''%''

DECLARE @COL_SELECT AS NVARCHAR(2000)

SET @COL_SELECT = 'SELECT DISTINCT column_name 
                   FROM information_schema.COLUMNS
                   WHERE table_name = ' + @table + '
                     AND column_name like ' + @modulo + @column + @modulo + ''

EXEC(@COL_SELECT)

错误：

Msg 402，Level 16，State 1，Line 6
数据类型varchar和varchar在模运算符中不兼容。

Answer 1

错误发生在这里：

DECLARE @modulo as NVARCHAR(5) = ''%'';

这被解释为查找两个空字符串的模数值

在这里使用单引号......

更新注意！

还有一点：您必须为表格的名称添加加倍的引号，并在的LIKE中添加以创建正确的声明...

DECLARE @COL_SELECT AS NVARCHAR(2000) SET @COL_SELECT = ' SELECT DISTINCT column_name FROM information_schema.COLUMNS WHERE table_name = ''' + @table + ''' AND column_name like ''' + @modulo + @column + @modulo + ''''

Answer 2

这样的事情应该运行良好：

my %h_tmp = $hash_ref;

打印会给你：

my %h_tmp = ();

此查询应该没有错误地执行。

Answer 3

威廉

在@table和@modulo变量之前和之后的@COL_SELECT中使用两个引号：

DECLARE @table as NVARCHAR(25) = 'proposals'
DECLARE @column as NVARCHAR(25) = 'daypart'
DECLARE @modulo as NVARCHAR(5) = '%'

DECLARE @COL_SELECT AS NVARCHAR(2000)
SET @COL_SELECT = '
    SELECT DISTINCT column_name 
    FROM information_schema.COLUMNS
    WHERE table_name = ''' + @table + '''
    AND column_name like ''' + @modulo + @column + @modulo + ''''

EXEC(@COL_SELECT)

希望它有所帮助。里卡多

具有LIKE条件的动态SQL

3 个答案:

更新注意！