SQL 手册SQL 函数数学函数ATAN本页总览ATANatandescriptionSyntaxDOUBLE atan(DOUBLE x) 返回x的反正切值,x为弧度值.examplemysql> select atan(0);+-----------+| atan(0.0) |+-----------+| 0 |+-----------+mysql> select atan(2);+--------------------+| atan(2.0) |+--------------------+| 1.1071487177940904 |+--------------------+keywordsATAN