SQL с нуля (лекция 2)

Типы данных

Числовые
Строковые
Календарные

Числовые

Tinyint, smallint, mediumint, int, bigint
BOOL = Tinyint(1) = Bit (1) =

Строковые

CHAR (m), VARCHAR (m)
TEXT and BLOB (tiny, medium and long)
ENUM, SET

Календарные

Date (YYYY-MM-DD)
Datetime (YYYY-MM-DD HH:MM:SS)
Timestamp (YYYYMMDDHHMMSS)
Year (YYYY)
Time (HH:MM:SS)

Дополнительные

NOT NULL
DEFAULT
UNIQUE
AUTO_INCREMENT
ZEROFILL

DDL (Data Definition Language) - язык описания данных DML (Data Manipulation Language)

CREATE
ALTER
DROP

DDL

CREATE TABLE table1
(column1 datatype EXTRA CONDITIONS,
PRIMARY KEY (column),
FOREIGN KEY (column) REFERENCES table2(COLUMN_F)

DDL

ALTER TABLE table1
ADD column_name date_type
DROP Column_name
MODIFY column_name datetype

DDL

DML

INSERT
UPDATE
DELETE

DML

INSERT INTO table_name VALUES (v1, v2, v2,,v4,v5);
INSERT INTO table_name (colum A,

DML

UPDATE tablename
SET column1 = value1, column15=value15
WHERE условие
DELETE FROM tablename WHERE условие;

DQL

SELECT
DISTINCT
WHERE
AND/OR, IN/BETWEEN, LIKE
ORDER BY