SQL Server?? ?? ??? ??? ?? ??? ???? ??? ??????
? ????? ???? ?? ? ???? ?? SQL Server?? ?? ??? ???? ???? ??? ?????. "SQL Server?? ?? ??? ???? ??"??? ??? ?? ?? ? ??? ? ???? ?? ??? ??? ???? ? ? ??? ???. ?? ???? ?? ?? ??? ???(CTE)? ?????.
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?? ??? CTE? ROW_NUMBER() ??? ???? ???? ?? ??? ?? ??? ???? ?? ???? ?????.
DECLARE @start DATE, @end DATE; SELECT @start = '20110714', @end = '20110717'; ;WITH n AS ( SELECT TOP (DATEDIFF(DAY, @start, @end) + 1) n = ROW_NUMBER() OVER (ORDER BY [object_id]) FROM sys.all_objects ) SELECT 'Bob', DATEADD(DAY, n-1, @start) FROM n;
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賓客姓名 | 日期 |
---|---|
Bob | 2011-07-14 |
Bob | 2011-07-15 |
Bob | 2011-07-16 |
Bob | 2011-07-17 |
?? ???? ??:
?? ??? ???? ?? ? ?? CTE? ???? ??? ?? ??? ?? ???? ??? ? ????.
DECLARE @t TABLE ( Member NVARCHAR(32), RegistrationDate DATE, CheckoutDate DATE ); INSERT @t SELECT N'Bob', '20110714', '20110717' UNION ALL SELECT N'Sam', '20110712', '20110715' UNION ALL SELECT N'Jim', '20110716', '20110719'; ;WITH [range](d,s) AS ( SELECT DATEDIFF(DAY, MIN(RegistrationDate), MAX(CheckoutDate))+1, MIN(RegistrationDate) FROM @t ), n(d) AS ( SELECT DATEADD(DAY, n-1, (SELECT MIN(s) FROM [range])) FROM (SELECT ROW_NUMBER() OVER (ORDER BY [object_id]) FROM sys.all_objects) AS s(n) WHERE n <= (SELECT MAX(d) FROM [range]) ) SELECT t.Member, n.d FROM n CROSS JOIN @t AS t WHERE n.d BETWEEN t.RegistrationDate AND t.CheckoutDate;
??:
賓客姓名 | 日期 |
---|---|
Bob | 2011-07-14 |
Bob | 2011-07-15 |
Bob | 2011-07-16 |
Bob | 2011-07-17 |
Sam | 2011-07-12 |
Sam | 2011-07-13 |
Sam | 2011-07-14 |
Sam | 2011-07-15 |
Jim | 2011-07-16 |
Jim | 2011-07-17 |
Jim | 2011-07-18 |
Jim | 2011-07-19 |
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TOSECIBERYNECTTOEREMOTEMYSQLSERVER, USESSHTUNNENG, CONFIGUREMYSQLFORREMOTEACCESS, SETFIREWALLRULES ? CONSIDERSSLENCRYPTION .First, SpectionANSSHTUNNELWITHSSH-L3307 : LocalHost : 3306user@remote-Server-NandConnectViamySQL-H127.0.1-P3307.second, editmys

MySQLDump? MySQL ??????? ??? ??? ???? ???? ?????. ??????? ???? ?? ?? ? ?? ?? ???? SQL ??? ?????. 1. ?? ??? ????? ??? ?????? ??? ???? ??? SQL ???? ?????. 2. ??? ?????? ?? ??? ??? ???? TB ?? ???? ?? ???? ???? ????. 3. ???? ???-single transaction,-databases,-all-databases,-routines ?; 4. MySQL ??? ???? ?? ?? ?? ?? ?? ? ??? ?? ??? ???? ? ????. 5. ??? ????? ????? ?? ? ?? ??? ???? ?? ????.

MySQL ??? ?? ??? ?? ?? ??? ?? ??? ??????. 1. ?? ?? ?? ?? ???? Slow_Query_Log ? Long_Query_Time; 2. ???? ??? ?? ??? ???? ? ????? query_time, lock_time, rows_examined? ?? ?? ??? ???? ????. 3. ??? ????? ???? ?? mysqldumpslow ?? pt-query idigest ??? ??????. 4. ??? ???? ??? ??, ??*???*, ??? ?? ?? ?? ?????. ?? ??, user_id? ???? ???? ?? ? ?? ?? ?? ??? ?? ???? ???? ? ????.

MySQL?? NULL ?? ?? ? ? 1. ???? ?? ? ? ? ??? NotNull? ???? ?? ??? NULL? ?????. 2. iSnull ?? ISNOTNULL = ??! =; 3. Ifnull ?? Coalesce ??? ????? ???? ???? ? ??? ? ????. 4. ?? ?? ????? NULL ?? ?? ??? ?? ???? ??? ?? ? ORM ??? ?? ?? ?????? ??????. NULL? ???? ?? ?? ???? ??? ???? ?? ?? ?? ????. ??? ???? ??, ?? ? ???? ?? ? ??? ?? ??? ??? ?? ???????. ??? ??? ???? ??? ?? ?? ??? ????? ?? ? ????.

MySQL ?????? ? ???? ??? ??? information_schema? ?? ????? ?? ? ??? ??? ? ????. 1. ?? ?????? ?? ?? : SQL ?? ???? selecttable_schemaas'database ', sum (data_length index_length)/1024/1024as'size (mb) 'frominformation_schema.tablessgroupbytable_schema; ?? ??????? ? ??? ??? ?? ??????? ???? ??? ?? ? ? ????. 2. ?? ??? ??? ?????? : selectta? ??????

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MySQL? ???? ??? ???? InnoDB ?? ??? ???? ??? ???? ???? ?????. 1. ????? ??? SQL ?? ????, ?? ?? ?? ?? ??? ?????. 2. ? ???? ???, ???, ?? ? ???? ?????. 3. ????? ???? ????? ??? STARTTRANSACTION, CONMING ? ROLLBACK???. 4. 4 ?? ?? ???? ?? ??, ?? ? ??, ?? ??? ?? ? ???? ?????. 5. ????? ???? ???? ?? ??? ??? ?? ??? ?? ?? ? ??? ????? ??????. ??? ????? ?? MySQL? ?? ???? ?? ??? ?? ? ? ????.
