PDF (US Ltr)
- 35.1Mb
PDF (A4)
- 35.2Mb
Man Pages (TGZ)
- 256.4Kb
Man Pages (Zip)
- 361.2Kb
Info (Gzip)
- 3.4Mb
Info (Zip)
- 3.4Mb
Search Results
https://dev.mysql.com/doc/refman/5.7/en/create-index.html
A UNIQUE index permits multiple NULL values for columns that can contain NULL. Otherwise, _rowid refers to the column in the first UNIQUE NOT NULL index if that index consists of a single integer column. If the first UNIQUE NOT NULL index does not ... CREATE [UNIQUE | FULLTEXT | SPATIAL] INDEX index_name [index_type] ON tbl_name (key_part,...) [index_option] [algorithm_option | lock_option] ...
https://dev.mysql.com/doc/refman/5.7/en/information-schema-optimization.html
row *************************** id: 1 select_type: SIMPLE table: VIEWS type: ALL possible_keys: NULL key: TABLE_SCHEMA,TABLE_NAME key_len: NULL ref: NULL rows: NULL Extra: Using where; Open_frm_only; Scanned 0 databases Use of constant database and ... Applications that monitor databases may make frequent use of INFORMATION_SCHEMA ...
https://dev.mysql.com/doc/refman/5.7/en/logical-operators.html
Table 12.5 Logical Operators Name Description AND, && Logical AND NOT, ! Negates value OR, || Logical OR XOR Logical XOR In SQL, all logical operators evaluate to TRUE, FALSE, or NULL (UNKNOWN). In MySQL, these are implemented as 1 (TRUE), 0 ...
https://dev.mysql.com/doc/refman/5.7/en/mysqldump.html
It is always enabled and attempting to disable it (--skip-secure-auth, --secure-auth=0) produces an error. NULL, 'NULL', and Empty Values: For a column named column_name, the NULL value, an empty string, and the string value 'NULL' are distinguished ... The mysqldump client utility performs logical backups, producing a set of SQL statements that can be executed to reproduce the original database object definitions and table ...
https://dev.mysql.com/doc/refman/5.7/en/replication-gtids-failover.html
There are a number of techniques when using MySQL Replication with Global Transaction Identifiers (GTIDs) for provisioning a new replica which can then be used for scaleout, being promoted to source as necessary for failover. Each identifier ...
https://dev.mysql.com/doc/refman/5.7/en/spatial-operator-functions.html
ST_Buffer(g, d [, strategy1 [, strategy2 [, strategy3]]]) Returns a geometry that represents all points whose distance from the geometry value g is less than or equal to a distance of d, or NULL if any argument is NULL. If the argument is an empty ... OpenGIS proposes a number of functions that can produce ...
https://dev.mysql.com/doc/refman/5.7/en/load-xml.html
Suppose that we have a table named person, created as shown here: USE test; CREATE TABLE person ( person_id INT NOT NULL PRIMARY KEY, fname VARCHAR(40) NULL, lname VARCHAR(40) NULL, created TIMESTAMP ); Suppose further that this table is initially ...The tagname in the optional ROWS IDENTIFIED BY clause must also be given as a literal string, and must be surrounded by angle brackets (< and ...
https://dev.mysql.com/doc/refman/5.7/en/outer-join-simplification.html
Instead, MySQL converts the query to a query with no outer join operation if the WHERE condition is null-rejected. (That is, it converts the outer join to an inner join.) A condition is said to be null-rejected for an outer join operation if it ...
https://dev.mysql.com/doc/refman/5.7/en/aggregate-functions.html
COUNT(expr) Returns a count of the number of non-NULL values of expr in the rows retrieved by a SELECT statement. mysql> SELECT student.student_name,COUNT(*) FROM student,course WHERE student.student_id=course.student_id GROUP BY student_name; ...
https://dev.mysql.com/doc/refman/5.7/en/gis-wkt-functions.html
If the geometry argument is NULL or not a syntactically well-formed geometry, or if the SRID argument is NULL, the return value is NULL. If the geometry argument is NULL or not a syntactically well-formed geometry, or if the SRID argument is NULL, ... These functions take as arguments a Well-Known Text (WKT) representation and, optionally, a spatial reference system identifier ...