SQL查询以获取列的精度值

本文介绍了SQL查询以获取列的精度值的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我需要一个SQL查询来获取某些列的精度值.我主要关注的是十进制类型的列，而我也需要相同的精度值.

I need a sql query that gets the precision value for certain columns.. I am mainly concerned with a decimal type column and I need the precision value for the same.

我意识到在某些版本和数据库服务器供应商中可以这样做.如果您可以列出其中的一些，那就太好了.

I realise that it is possible to do so in certain versions and vendors of database servers. It would be nice if you could list down for a few of them.

推荐答案

Oracle:

SELECT DATA_LENGTH, DATA_PRECISION FROM ALL_TAB_COLUMNS WHERE TABLE_NAME = :TableName AND COLUMN_NAME = :ColumnName

Firebird(+ Interbase):

Firebird (+ Interbase) :

SELECT rdb$field_scale, rdb$field_precision FROM rdb$relations r JOIN rdb$relation_fields rf ON rf.rdb$relation_name = r.rdb$relation_name JOIN rdb$fields fld ON rf.rdb$field_source = fld.rdb$field_name WHERE r.rdb$relation_name = :TableName AND rf.rdb$field_name = :ColumnName

MySql(未测试！):

MySql (Not Tested !) :

SELECT NUMERIC_PRECISION, NUMERIC_SCALE FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = :TableName AND COLUMN_NAME = :ColumnName