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https://dev.mysql.com/doc/refman/8.4/en/signal.html
To retrieve information from the diagnostics area, use the GET DIAGNOSTICS statement (see Section 15.6.7.3, “GET DIAGNOSTICS Statement”). SIGNAL Overview Signal Condition Information Items Effect of Signals on Handlers, Cursors, and Statements ...SIGNAL provides error information to a handler, to an outer portion of the application, or to the ...
https://dev.mysql.com/doc/refman/8.4/en/analyze-table.html
To check the stored key distribution cardinality, use the SHOW INDEX statement or the INFORMATION_SCHEMA STATISTICS table. See Section 15.7.7.23, “SHOW INDEX Statement”, and Section 28.3.34, “The INFORMATION_SCHEMA STATISTICS Table”. ANALYZE ...ANALYZE [NO_WRITE_TO_BINLOG | LOCAL] TABLE tbl_name UPDATE HISTOGRAM ON col_name [, col_name] ...
https://dev.mysql.com/doc/refman/8.4/en/lock-tables.html
Another use for UNLOCK TABLES is to release the global read lock acquired with the FLUSH TABLES WITH READ LOCK statement, which enables you to lock all tables in all databases. Table Lock Acquisition Table Lock Release Interaction of Table Locking ... LOCK {TABLE | TABLES} tbl_name [[AS] alias] lock_type [, tbl_name [[AS] alias] lock_type] ...
https://dev.mysql.com/doc/refman/8.4/en/select.html
A SELECT statement can start with a WITH clause to define common table expressions accessible within the SELECT. The most commonly used clauses of SELECT statements are these: Each select_expr indicates a column that you want to retrieve. The ...
https://dev.mysql.com/doc/refman/8.4/en/insert-on-duplicate.html
If you specify an ON DUPLICATE KEY UPDATE clause and a row to be inserted would cause a duplicate value in a UNIQUE index or PRIMARY KEY, an UPDATE of the old row occurs. If column b is also unique, the INSERT is equivalent to this UPDATE statement ...With ON DUPLICATE KEY UPDATE, the affected-rows value per row is 1 if the row is inserted as a new row, 2 if an existing row is updated, and 0 if an existing row is set to its current ...
https://dev.mysql.com/doc/refman/8.4/en/implicit-commit.html
(This does not apply to other operations on temporary tables such as ALTER TABLE and CREATE INDEX, which do cause a commit.) However, although no implicit commit occurs, neither can the statement be rolled back, which means that the use of such ...
https://dev.mysql.com/doc/refman/8.4/en/alter-database.html
If the database name is omitted, the statement applies to the default database. For any alter_option omitted from the statement, the database retains its current option value, with the exception that changing the character set may change the ...
https://dev.mysql.com/doc/refman/8.4/en/create-table-select.html
If you want to have indexes in the created table, you should specify these before the SELECT statement: mysql> CREATE TABLE bar (UNIQUE (n)) SELECT n FROM foo; For CREATE TABLE ... You can create one table from another by adding a SELECT statement ...For example: mysql> CREATE TABLE test (a INT NOT NULL AUTO_INCREMENT, -> PRIMARY KEY (a), KEY(b)) -> ENGINE=InnoDB SELECT b,c FROM test2; This creates an InnoDB table with three columns, a, b, and ...
https://dev.mysql.com/doc/refman/8.4/en/create-view.html
The select_statement is a SELECT statement that provides the definition of the view. (Selecting from the view selects, in effect, using the SELECT statement.) The select_statement can select from base tables or from other views. The SELECT statement ...If the view does not exist, CREATE OR REPLACE VIEW is the same as CREATE ...
https://dev.mysql.com/doc/refman/8.4/en/get-diagnostics.html
GET [CURRENT | STACKED] DIAGNOSTICS { statement_information_item [, statement_information_item] ... The GET DIAGNOSTICS statement is typically used in a handler within a stored program. It is a MySQL extension that GET [CURRENT] DIAGNOSTICS is ...