如何使用SQL命令在C#中实现此计划?
我有两张桌子:
- 表1
name_markaz nvarchar(100)
,code_markaz nchar(20)
; - 表2
name_markaz nvarchar(100)
,code_markaz nchar(20)
;
我想实现这个计划,从表1中读取所有数据,并在这个条件下插入表2:
if table1.code_markaz not found in table 2.code_markaz then insert the table1.code_markaz into the table2.code_markaz
我认为这个查询可以做到(我更喜欢使用EXISTS
):
INSERT INTO table2 (name_markaz, code_markaz) SELECT name_markaz, code_markaz FROM table1 WHERE NOT EXISTS (SELECT 1 FROM table2 ti WHERE ti.code_markaz = table1.code_markaz);