两表(多表)关联update的写法

 

SQL Server示例: update a set a.gqdltks=b.gqdltks,a.bztks=b.bztks from landleveldata a,gdqlpj b where a.GEO_Code=b.lxqdm

Oracle语法: UPDATE updatedtable SET (col_name1[,col_name2...])= (SELECT col_name1,[,col_name2...] FROM srctable [WHERE where_definition])

Oracel 示例: update landleveldata a set (a.gqdltks, a.bztks)= (select b.gqdltks, b.bztks from gdqlpj b where a.GEO_Code=b.lxqdm)

MySQL语法: UPDATE table_references SET col_name1=expr1 [, col_name2=expr2 ...] [WHERE where_definition]

MySQL 示例: update landleveldata a, gdqlpj b set a.gqdltks= b.gqdltks, a.bztks= b.bztks where a.GEO_Code=b.lxqdm