MySQL (C API) VC example and code download (1)_PHP tutorial

1. Description: Copy table (only copy structure, source table name: a, new table name: b)

SQL: select * into b from a where 1 1

2. Description: Copy table (copy data, source table name: a target table name: b)

SQL: insert into b(a, b, c) select d,e,f from b;

3. Description: Display the article, submitter and last reply time

SQL: select a.title,a .username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b

4. Description: Outer join query (table name 1: a Table name 2: b)

SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUTER JOIN b ON a.a = b.c

5 .Description: Schedule reminder five minutes in advance

SQL: select * from schedule where datediff('minute',f start time,getdate())>5

6. Description: Two related tables, delete the information in the main table that is not in the secondary table

SQL:

delete from info where not exists ( select * from infobz where info.infid=infobz.infid )

Explanation: --

SQL:

SELECT A.NUM, A.NAME, B.UPD_DATE, B.PREV_UPD_DATE

FROM TABLE1,

(SELECT X.NUM, FROM TABLE2

WHERE TO_CHAR(UPD_DATE,'YYYY/MM') = TO_CHAR(SYSDATE, 'YYYY/MM')) X,

(SELECT NUM, UPD_DATE, STOCK_ONHAND

FROM TABLE2

WHERE TO_CHAR(UPD_DATE,'YYYY/MM') =

TO_CHAR(TO_DATE(TO_CHAR(SYSDATE, 'YYYY/MM') || '/01',' YYYY/MM/DD') - 1, 'YYYY/MM') ) Y,

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