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SQLite Reset Primary Key Field
I have a few tables in SQLite and I am trying to figure out how to reset the auto-incremented database field.
4 Answers
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Equals(=) vs. LIKE
...rmance:
A personal example using mysql 5.5: I had an inner join between 2 tables, one of 3 million rows and one of 10 thousand rows.
When using a like on an index as below(no wildcards), it took about 30 seconds:
where login like '12345678'
using 'explain' I get:
When using an '=' on the s...
How does a PreparedStatement avoid or prevent SQL injection?
...);
If "user" came from user input and the user input was
Robert'); DROP TABLE students; --
Then in the first instance, you'd be hosed. In the second, you'd be safe and Little Bobby Tables would be registered for your school.
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Why would you use Expression rather than Func?
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@bertl Delegate is what CPU sees (executable code of one architecture), Expression is what compiler sees (merely another format of source code, but still source code).
– codewarrior
May 5 '17 at 9:22
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Altering a column to be nullable
I want to alter a table column to be nullable. I have used:
10 Answers
10
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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...
MySQL LIKE IN()?
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Over 1 million rows in my table. REGEX arround 0.0009 and LIKE arround 0.0005. If more then 5 REGEX, arround 0.0012...
– David Bélanger
Nov 26 '11 at 5:24
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SQL to find the number of distinct values in a column
...aggregate function:
SELECT COUNT(DISTINCT column_name) AS some_alias FROM table_name
This will count only the distinct values for that column.
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Rails 4: List of available datatypes
... is not set to use :sql, then your schema.rb file wont be able to dump the table that uses types like :json. The schema will still be dumped for the tables that use default types but you'll see a comment for the table with special types like, "could not dump table...". Look here to set the schema_fo...
Stored procedure slow when called from web, fast from Management Studio
... change:
ALTER PROCEDURE [dbo].[sproc]
@param1 int,
AS
SELECT * FROM Table WHERE ID = @param1
to:
ALTER PROCEDURE [dbo].[sproc]
@param1 int,
AS
DECLARE @param1a int
SET @param1a = @param1
SELECT * FROM Table WHERE ID = @param1a
Seems strange, but it fixed my problem.
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