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Create unique constraint with null columns
I have a table with this layout:
4 Answers
4
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How to change collation of database, table, column?
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You need to either convert each table individually:
ALTER TABLE mytable CONVERT TO CHARACTER SET utf8mb4
(this will convert the columns just as well), or export the database with latin1 and import it back with utf8mb4.
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Using varchar(MAX) vs TEXT on SQL Server
...hould use a Full Text Index.
LIKE is simpler to implement and is often suitable for small amounts of data, but it has extremely poor performance with large data due to its inability to use an index.
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Replacing NAs with latest non-NA value
In a data.frame (or data.table), I would like to "fill forward" NAs with the closest previous non-NA value. A simple example, using vectors (instead of a data.frame ) is the following:
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How to check if a Constraint exists in Sql server?
...QUE, PRIMARY KEY, and/or FOREIGN KEY
SELECT *
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS
WHERE CONSTRAINT_NAME='XYZ'
--Returns one row for each FOREIGN KEY constrain
SELECT *
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS
WHERE CONSTRAINT_NAME='XYZ'
--Returns one row for eac...
UITableView with fixed section headers
Greets,
I'm reading that the default behaviour of UITableView is to pin section header rows to the top of the table as you scroll through the sections until the next section pushes the previos section row out of view.
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SQL Server insert if not exists best practice
I have a Competitions results table which holds team member's names and their ranking on one hand.
8 Answers
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What should I name a table that maps two tables together? [closed]
Let's say I have two tables:
24 Answers
24
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How to get the next auto-increment id in mysql
How to get the next id in mysql to insert it in the table
19 Answers
19
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“where 1=1” statement [duplicate]
I saw some people use a statement to query a table in a MySQL database like the following:
10 Answers
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