函数编号类别ORACLEMYSQL注释1数字函数round(1.23456,4)round(1.23456,4)一样:ORACLE:select round(1.23456,4) value from dualMYSQL:select round(1.23456,4) value2abs(-1)abs(-1)功能:将当前数据取绝对值用法: oracle和mysql用法一样mysql: s..
其它编号类别ORACLEMYSQL注释1内连接的更改1、select a.*, b.*, c.*, d.* from a, b, c, dwhere a.id = b.id and a.name is not null and a.id = c.id(+) and a.id = d.id(+)"(+)"所在位置的另一侧为连接的方向,所以上面的例子1是左连接。以下的例..