1

如果它们不存在，我正在尝试将 som 列动态添加到 2 个表中。我的问题是，列的名称取决于另一列的值。

但显然以下是不允许的，为什么？

declare @inputs int; 
set @inputs = (select inputs from campaigns where id = 102) + 1; 
update campaigns set inputs = @inputs where id = 102; 
if col_length('campaigns', 'input' + @inputs) is null alter table campaigns add input' + @inputs + ' ntext null; 
if col_length('campaigns', 'input' + @inputs + 'text') is null alter table campaigns add input' + @inputs + 'ivocall ntext null; 
if col_length('rapports', 'input' + @inputs) is null alter table rapports add input' + @inputs + ' ntext null; 
if col_length('rapports', 'input' + @inputs + 'values') is null alter table rapports add input' + @inputs + 'values ntext null; 
update campaigns set input' + @inputs + ' = '1||test||||0||0||0||0||0||2||0' where id = 102

我收到以下错误

Msg 102, Level 15, State 1, Line 4
Incorrect syntax near ' + @inputs + '.
Msg 102, Level 15, State 1, Line 5
Incorrect syntax near ' + @inputs + '.
Msg 102, Level 15, State 1, Line 6
Incorrect syntax near ' + @inputs + '.
Msg 102, Level 15, State 1, Line 7
Incorrect syntax near ' + @inputs + '.
Msg 102, Level 15, State 1, Line 8
Incorrect syntax near ' + @inputs + '.
4

1 回答 1

1

看这个：

if col_length('campaigns', 'input' + @inputs) is null 
    alter table campaigns 
    add input' + @inputs + ' ntext null;

第三行是不对的，充其量应该是：

if col_length('campaigns', 'input' + @inputs) is null 
    alter table campaigns 
    add 'input' + @inputs ntext null;

然而，即使这样也行不通。您最好将整个 DDL 语句创建为字符串，然后执行它。就像是：

set @sql = 'alter table campaigns add column input' + @inputs + ' ntext null'
exec (@sql)
于 2012-07-02T17:54:23.490 回答