数据库元数据数据字典查询_11_列出数据库里含有自增的字段

                           列出数据库里含有自增的字段

需求描述

需求：查询数据库里所有自增类型的字段

解决方法：通过数据字典里的字段is_identity来实现该需求。

注: 数据库数据集SQL脚本详见如下链接地址

​​员工表结构和数据初始化SQL脚本​​

SQL代码

-- mysql 查看是否自增
SELECT * FROM
(
    select ORDINAL_POSITION as Colorder,Column_Name as ColumnName,data_type as TypeName,COLUMN_COMMENT as DeText,
    (case when data_type = 'float' or data_type = 'double' or data_type = 'decimal' then  NUMERIC_PRECISION else CHARACTER_MAXIMUM_LENGTH end ) as length,
    NUMERIC_SCALE as Scale,( case when EXTRA='auto_increment' then 1 else 0 end) as IsIdentity,(case when COLUMN_KEY='PRI' then 1 else 0 end) as IsPK,
    (case when IS_NULLABLE = 'NO' then 0 else 1 end)as CanNull,COLUMN_DEFAULT as DefaultVal
    from information_schema.columns 
    where table_schema = 'kettlexp'  
    order by ORDINAL_POSITION asc
)A
ddWHERE IsIdentity=1

执行结果

-- SQL Server
use kettlexp
go
SELECT OBJECT_NAME(OBJECT_ID) 表名,NAME 字段名 
FROM SYS.COLUMNS 
WHERE IS_IDENTITY=1