A.select B.show C.DESC D.display
A.altertable表名createprimarykey(字段列表) B.altertable表名addprimarykey(字段列表) C.addtable表名createprimarykey(字段列表) D.addtable表名changeprimarykey(字段列表)
A.altertable表名deleteprimarykey B.altertable表名removeprimarykey C.altertable表名dropprimarykey D.changetable表名deleteprimarykey