附加查询返回的值

Question

I am trying to return all data of exp_matrix_data.col_id_1

select col_id_

(select col_id from exp_matrix_cols 
left join exp_channel_fields on exp_matrix_cols.field_id = exp_channel_fields.field_id
where exp_channel_fields.field_name = 'transfer_agreement_field'
and exp_matrix_cols.col_name = 'school_name')

from exp_matrix_data

the select within the ( ) returns 1, that retrieves the correct id to be added to col_id_, so I can do:

select col_id_1 from exp_matrix_data

This does not work, but will give you an idea of what I am trying to accomplish.

Answer 1

您需要使用动态查询，请阅读以下内容： http : //dev.mysql.com/doc/refman/5.0/en/sql-syntax-prepared-statements.html