大约有 6,100 项符合查询结果(耗时:0.0287秒) [XML]

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How to find gaps in sequential numbering in mysql?

We have a database with a table whose values were imported from another system. There is an auto-increment column, and there are no duplicate values, but there are missing values. For example, running this query: ...
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Improving bulk insert performance in Entity framework [duplicate]

I want to insert 20000 records in a table by entity framework and it takes about 2 min. Is there any way other than using SP to improve its performance. This is my code: ...
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How can I join multiple SQL tables using the IDs?

I have 4 different tables that I want to join. The tables are structured with columns as follows: 4 Answers ...
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How to have an automatic timestamp in SQLite?

... Just declare a default value for a field: CREATE TABLE MyTable( ID INTEGER PRIMARY KEY, Name TEXT, Other STUFF, Timestamp DATETIME DEFAULT CURRENT_TIMESTAMP ); However, if your INSERT command explicitly sets this field to NULL, it will be set to NULL. ...
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quick random row selection in Postgres

I have a table in postgres that contains couple of millions of rows. I have checked on the internet and I found the following ...
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SQL Server 2005 How Create a Unique Constraint?

How do I create a unique constraint on an existing table in SQL Server 2005? 10 Answers ...
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Simple way to calculate median with MySQL

...ike: place / median for that place... like select place, median_value from table... any way? thanks – saulob Jan 18 '14 at 4:45 2 ...
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Tools to generate database tables diagram with Postgresql? [closed]

Are there any free tools to generate tables diagrams with Postgresql? 7 Answers 7 ...
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CSS display: table min-height not working

...e know I can make min-height work with the latest browsers? I am using CSS tables and it seems to ignore min-height. 4 Answ...
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Why does X[Y] join of data.tables not allow a full outer join, or a left join?

This is a bit of a philosophical question about data.table join syntax. I am finding more and more uses for data.tables, but still learning... ...