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Multiple Updates in MySQL
... use INSERT ... ON DUPLICATE KEY UPDATE.
Using your example:
INSERT INTO table (id,Col1,Col2) VALUES (1,1,1),(2,2,3),(3,9,3),(4,10,12)
ON DUPLICATE KEY UPDATE Col1=VALUES(Col1),Col2=VALUES(Col2);
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T-SQL: Using a CASE in an UPDATE statement to update certain columns depending on a condition
...tructure of your query, just the data involved. You could do this:
update table set
columnx = (case when condition then 25 else columnx end),
columny = (case when condition then columny else 25 end)
This is semantically the same, but just bear in mind that both columns will always be upda...
It has a DefiningQuery but no InsertFunction element… err
...
Well when a table is encountered without a PrimaryKey it is treated as a View.
And views show up in the EDMX file (open in an XML editor to see) in the StorageModel\EntitySet[n]\DefiningQuery element.
When you have a DefiningQuery the ...
中文网（自研/维护）拓展 · App Inventor 2 中文网
...otherwise.
DatabasePath()
Returns the path to the database.
Delete(table,whereClause,bindParams)
Executes a SQL DELETE statement.
DeleteAsync(tag,table,whereClause,bindParams)
Executes a SQL DELETE statement, asynchronously.
DeleteDatabase()
Delete the database.
Execute(sql,bi...
How important is the order of columns in indexes?
...index pages that the optimiser must scan; this can be significant in large tables with millions of rows
– Paul Hatcher
Oct 28 '16 at 14:58
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SQL MAX of multiple columns?
...(VALUES (date1), (date2), (date3),...) AS value(v)) as [MaxDate]
FROM [YourTableName]
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How to enable MySQL Query Log?
...make sure is that the directory and file being written to exists and is writable by mysql.
– NightOwlPrgmr
Sep 28 '18 at 19:10
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Is the primary key automatically indexed in MySQL?
...m/doc/refman/5.5/en/optimizing-primary-keys.html
The primary key for a table represents the column or set of columns
that you use in your most vital queries. It has an associated index,
for fast query performance
For MySQL 5.0 reference see: http://dev.mysql.com/doc/refman/5.0/en/mysql-ind...
Updating MySQL primary key
I have a table user_interactions with 4 columns:
3 Answers
3
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Change limit for “Mysql Row size too large”
... the following to the my.cnf file under [mysqld] section.
innodb_file_per_table=1
innodb_file_format = Barracuda
ALTER the table to use ROW_FORMAT=COMPRESSED.
ALTER TABLE nombre_tabla
ENGINE=InnoDB
ROW_FORMAT=COMPRESSED
KEY_BLOCK_SIZE=8;
There is a possibility that the above sti...