数据操作语言——使用SELECT命令查询表中数据的语法如下:SELECT * | {[DISTINCT] column | expression [alias],…} FROM table; 例如:SQL> SELECT * FROM vendorMaster; SQL> SELECT vencode, venname, telNo FROM vendorMaster; 若要避免选择重复行,请在SELECT命令中添加DISTINCT子句。示例:SQL> SELECT DISTINCT vencode FROM vendorMaster; 带有WHERE子句的SELECT命令语法如下:SELECT * | {[DISTINCT] column | expression [alias],…} FROM table WHERE condition(s); 例如:SELECT * FROM orderMaster WHERE vencode='V004' ORDER BY delDate;