sqlite3學習之常規化語法格式
SQLite 是遵循一套獨特的稱為語法的規則和準則,我們著重需要注意的是,SQLite 是不區分大小寫的,但也有一些命令是大小寫敏感的,比如 GLOB 和 glob 在 SQLite 的語句中有不同的含義。
SQLite 註釋是附加的註釋,可以在 SQLite 程式碼中添加註釋以增加其可讀性,他們可以出現在任何空白處,包括在表示式內和其他 SQL 語句的中間,但它們不能巢狀。SQL 註釋以兩個連續的 "-" 字元(ASCII 0x2d)開始,並擴充套件至下一個換行符(ASCII 0x0a)或直到輸入結束,以先到者為準。我們也可以使用 C 風格的註釋,以 "/*" 開始,並擴充套件至下一個 "*/" 字元對或直到輸入結束,以先到者為準。並且SQLite的註釋可以跨越多行。例項如下:
.help -- 這是一個簡單的註釋
sqlite3的語法格式就是,所有的 SQLite 語句可以以任何關鍵字開始,如 SELECT、INSERT、UPDATE、DELETE、ALTER、DROP 等,所有的語句以分號(;)結束,下面我們就來具體的看下各種語法格式是如何來使用的。
SQLite ANALYZE 語句:
ANALYZE;
or
ANALYZE database_name;
or
ANALYZE database_name.table_name;
SQLite AND/OR 子句:
SELECT column1, column2....columnN FROM table_name WHERE CONDITION-1 {AND|OR} CONDITION-2;
SQLite ALTER TABLE 語句:
ALTER TABLE table_name ADD COLUMN column_def...;
SQLite ALTER TABLE 語句(Rename):
ALTER TABLE table_name RENAME TO new_table_name;
SQLite ATTACH DATABASE 語句:
ATTACH DATABASE 'DatabaseName' As 'Alias-Name';
SQLite BEGIN TRANSACTION 語句:
BEGIN; or BEGIN EXCLUSIVE TRANSACTION;
SQLite BETWEEN 子句:
SELECT column1, column2....columnN
FROM table_name
WHERE column_name BETWEEN val-1 AND val-2;
SQLite COMMIT 語句:
COMMIT;
SQLite CREATE INDEX 語句:
CREATE INDEX index_name
ON table_name ( column_name COLLATE NOCASE );
SQLite CREATE UNIQUE INDEX 語句:
CREATE UNIQUE INDEX index_name
ON table_name ( column1, column2,...columnN);
SQLite CREATE TABLE 語句:
CREATE TABLE table_name(
column1 datatype,
column2 datatype,
column3 datatype,
.....
columnN datatype,
PRIMARY KEY( one or more columns )
);
SQLite CREATE TRIGGER 語句:
CREATE TRIGGER database_name.trigger_name
BEFORE INSERT ON table_name FOR EACH ROW
BEGIN
stmt1;
stmt2;
....
END;
SQLite CREATE VIEW 語句:
CREATE VIEW database_name.view_name AS
SELECT statement....;
SQLite CREATE VIRTUAL TABLE 語句:
CREATE VIRTUAL TABLE database_name.table_name USING weblog( access.log );
or
CREATE VIRTUAL TABLE database_name.table_name USING fts3( );
SQLite COMMIT TRANSACTION 語句:
COMMIT;
SQLite COUNT 子句:
SELECT COUNT(column_name)
FROM table_name
WHERE CONDITION;
SQLite DELETE 語句:
DELETE FROM table_name
WHERE {CONDITION};
SQLite DETACH DATABASE 語句:
DETACH DATABASE 'Alias-Name';
SQLite DISTINCT 子句:
SELECT DISTINCT column1, column2....columnN
FROM table_name;
SQLite DROP INDEX 語句:
DROP INDEX database_name.index_name;
SQLite DROP TABLE 語句:
DROP TABLE database_name.table_name;
SQLite DROP VIEW 語句:
DROP VIEW view_name;
SQLite DROP TRIGGER 語句:
DROP TRIGGER trigger_name
SQLite EXISTS 子句:
SELECT column1, column2....columnN
FROM table_name
WHERE column_name EXISTS (SELECT * FROM table_name );
SQLite EXPLAIN 語句:
EXPLAIN INSERT statement...;
or
EXPLAIN QUERY PLAN SELECT statement...;
SQLite GLOB 子句:
SELECT column1, column2....columnN
FROM table_name
WHERE column_name GLOB { PATTERN };
SQLite GROUP BY 子句:
SELECT SUM(column_name)
FROM table_name
WHERE CONDITION
GROUP BY column_name;
SQLite HAVING 子句:
SELECT SUM(column_name)
FROM table_name
WHERE CONDITION
GROUP BY column_name
HAVING (arithematic function condition);
SQLite INSERT INTO 語句:
INSERT INTO table_name( column1, column2....columnN)
VALUES ( value1, value2....valueN);
SQLite IN 子句:
SELECT column1, column2....columnN
FROM table_name
WHERE column_name IN (val-1, val-2,...val-N);
SQLite Like 子句:
SELECT column1, column2....columnN
FROM table_name
WHERE column_name LIKE { PATTERN };
SQLite NOT IN 子句:
SELECT column1, column2....columnN
FROM table_name
WHERE column_name NOT IN (val-1, val-2,...val-N);
SQLite ORDER BY 子句:
SELECT column1, column2....columnN
FROM table_name
WHERE CONDITION
ORDER BY column_name {ASC|DESC};
SQLite PRAGMA 語句:
PRAGMA pragma_name;
For example:
PRAGMA page_size;
PRAGMA cache_size = 1024;
PRAGMA table_info(table_name);
SQLite RELEASE SAVEPOINT 語句:
RELEASE savepoint_name;
SQLite REINDEX 語句:
REINDEX collation_name;
REINDEX database_name.index_name;
REINDEX database_name.table_name;
SQLite ROLLBACK 語句:
ROLLBACK;
or
ROLLBACK TO SAVEPOINT savepoint_name;
SQLite SAVEPOINT 語句:
SAVEPOINT savepoint_name;
SQLite SELECT 語句:
SELECT column1, column2....columnN
FROM table_name;
SQLite UPDATE 語句:
UPDATE table_name
SET column1 = value1, column2 = value2....columnN=valueN
[ WHERE CONDITION ];
SQLite VACUUM 語句:
VACUUM;
SQLite WHERE 子句:
SELECT column1, column2....columnN
FROM table_name
WHERE CONDITION;
好啦,本次記錄就到這裡了。
如果感覺不錯的話,請多多點贊支援哦。。。