https://dev.mysql.com/control-flow-functions.html
If all types are character string (CHAR or VARCHAR), the result is VARCHAR with maximum length determined by the longest character length of the operands. If all types are character or binary string, the result is VARBINARY. SET and ENUM are treated ...The second syntax returns the result for the first condition that is ...
https://dev.mysql.com/crashing.html
If you have a problem with tables containing dynamic-length rows and you are using only VARCHAR columns (not BLOB or TEXT columns), you can try to change all VARCHAR to CHAR with ALTER TABLE. Each MySQL version is tested on many platforms before it ...
https://dev.mysql.com/create-table-select.html
The same is true for other CREATE TABLE options such as CHARSET. For example, the AUTO_INCREMENT attribute is not preserved, and VARCHAR columns can become CHAR columns. Retrained attributes are NULL (or NOT NULL) and, for those columns that have ...
https://dev.mysql.com/csv-storage-engine.html
The CSV storage engine stores data in text files using comma-separated values format. The CSV storage engine is always compiled into the MySQL server. To examine the source for the CSV engine, look in the storage/csv directory of a MySQL source ...
https://dev.mysql.com/cursors.html
Cursors have these properties: Asensitive: The server may or may not make a copy of its result table Read only: Not updatable Nonscrollable: Can be traversed only in one direction and cannot skip rows Cursor declarations must appear before handler ...
https://dev.mysql.com/derived-tables.html
For information about lateral derived tables preceded by the LATERAL keyword, see Section 13.2.11.9, “Lateral Derived Tables”. A derived table is an expression that generates a table within the scope of a query FROM clause. For example, a ...
https://dev.mysql.com/dynamic-format.html
Dynamic storage format is used if a MyISAM table contains any variable-length columns (VARCHAR, VARBINARY, BLOB, or TEXT), or if the table was created with the ROW_FORMAT=DYNAMIC table option. Dynamic-format tables have these characteristics: All ...Dynamic format is a little more complex than static format because each row has a header that indicates how long it ...
https://dev.mysql.com/enum.html
Note that ENUM columns can be assigned a character set and collation. Make sure that the column is sorted lexically rather than by index number by coding ORDER BY CAST(col AS CHAR) or ORDER BY CONCAT(col). An ENUM is a string object with a value ...
https://dev.mysql.com/example-foreign-keys.html
In MySQL, InnoDB tables support checking of foreign key constraints. See Chapter 15, The InnoDB Storage Engine, and Section 1.8.2.3, “FOREIGN KEY Constraint Differences”. A foreign key constraint is not required merely to join two tables. It is ...
https://dev.mysql.com/examples.html
Here are examples of how to solve some common problems with MySQL. Some of the examples use the table shop to hold the price of each article (item number) for certain traders (dealers). Supposing that each trader has a single fixed price per ...
