SQL查询多个表

Question

我有4个表，一个是veg_tech，其结构是

CREATE TABLE IF NOT EXISTS `veg_tech` (
`VEG_TECH_ID` int(11) NOT NULL,
  `VALI` varchar(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL,
  `JAAT` varchar(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL,
  `BOR_ID` int(11) NOT NULL,
  `FERTILIZER_KG_ROP_ID` int(11) NOT NULL,
  `BOR_DISTANCE_ID` int(11) NOT NULL,
  `BEW_BARNA_DAR` varchar(255) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

现在，BOR_ID，FERTILIZER_KG_ROP_ID和DOR_DISTANCE_ID是外键，现在外表也有数据，我也想显示该表中的所有数据以及其他表中的所有数据。 有人可以帮忙吗

Answer 1

只需使用联接：

SELECT * 
FROM 'veg_tech' v
LEFT JOIN table_2 t2 ON v.BOR_ID= t2.BOR_ID
LEFT JOIN table_3 t3 ON v.FERTILIZER_KG_ROP_ID = t.FERTILIZER_KG_ROP_ID 
LEFT JOIN table_4 t4 ON v.DOR_DISTANCE_ID = t4.DOR_DISTANCE_ID ;