Mysql/CheatSheet: Difference between revisions
< Mysql
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* Storage Engines | * Storage Engines | ||
** MyISAM (optimized for compression and speed. portable. not transaction safe. used to be default) | ** MyISAM (optimized for compression and speed. portable. not transaction safe. used to be default) | ||
** InnoDB (optimized for speed | ** InnoDB (optimized for speed. portable. default) | ||
** MERGE | ** MERGE | ||
** MEMORY (HEAP) | ** MEMORY (HEAP) |
Revision as of 18:12, 17 June 2020
Databases
- Create
CREATE DATABASE [IF NOT EXISTS] database_name;
- Use
USE database_name;
- Delete
DROP DATABASE [IF EXISTS] database_name;
- List all
SHOW DATABASES;
- Storage Engines
- MyISAM (optimized for compression and speed. portable. not transaction safe. used to be default)
- InnoDB (optimized for speed. portable. default)
- MERGE
- MEMORY (HEAP)
- ARCHIVE
- CSV
- FEDERATED
Tables
- list
SHOW TABLES;
- create
CREATE TABLE [IF NOT EXISTS] table_name( column1 datatype constraint, column2 datatype constraint );
CREATE TABLE IF NOT EXISTS cars( vehicle_id INT AUTO_INCREMENT PRIMARY KEY, title VARCHAR(255) NOT NULL, first_seen DATE, description TEXT );
- constraints
NOT NULL UNIQUE PRIMARY KEY (NOT NULL and UNIQUE) FOREIGN KEY CHECK DEFAULT INDEX
data types
TINYINT (A very small integer: -128/128 or 0/255) SMALLINT (A small integer: -32768/32767 or 0/65535) MEDIUMINT (A medium-sized integer: -8388608/8388607 or 0/16777215) INT (A standard integer: -2147483648/2147483647 or 0/4294967295) BIGINT (A large integer: -9223372036854775808/9223372036854775807 or 0/18446744073709551615) DECIMAL(P,D) (A fixed-point number: P=digits(max=65), D=decimals(max=30)) DEC (=DECIMAL) FLOAT (A single-precision floating point number DOUBLE (A double-precision floating point number BIT (A bit field CHAR (A fixed-length nonbinary (character) string VARCHAR (A variable-length non-binary string BINARY (A fixed-length binary string VARBINARY (A variable-length binary string TINYBLOB (A very small BLOB (binary large object) BLOB (A small BLOB MEDIUMBLOB (A medium-sized BLOB LONGBLOB (A large BLOB TINYTEXT (A very small non-binary string TEXT (A small non-binary string MEDIUMTEXT (A medium-sized non-binary string LONGTEXT (A large non-binary string ENUM (An enumeration; each column value may be assigned one enumeration member SET (A set; each column value may be assigned zero or more SET members DATE (A date value: YYYY-MM-DD) TIME (A time value: hh:mm:ss) DATETIME (A date and time value: YYYY-MM-DD hh:mm:ssformat TIMESTAMP (A timestamp value: YYYY-MM-DD hh:mm:ss YEAR (A year value: YYYY)