问题描述 笛卡尔积数据处理问题,求大神指导 表结构:tableName(cgi,lo,la,derection,city) SQL: SELECT t1.cgi AS s_cgi, t1.lo AS s_lo, t1.derection AS s_derection, t2.cgi AS t_cgi, t2.lo AS t_lo, t2.derection AS t_derection FROM tableName t1, tableName t2 WHERE t1.city = 'GZ' AN