一個SQLite數(shù)據(jù)庫查詢數(shù)據(jù)的代碼實例
我們知道,在SQL Server數(shù)據(jù)庫中查詢數(shù)據(jù)時需要用到SELECT……FROM語句結(jié)合WHERE條件來實現(xiàn)的,其實SQLite數(shù)據(jù)庫查詢數(shù)據(jù)的方式也是這樣的,本文通過一個實例來介紹這一過程,希望能給大家?guī)硎斋@。
首先將下面的SQL 語句保存到 data.sql 文件中(為了以后的練習(xí)使用):
- BEGIN TRANSACTION;
 - CREATE TABLE Cars(Id integer PRIMARY KEY, Name text, Cost integer);
 - INSERT INTO Cars VALUES(1,'Audi',52642);
 - INSERT INTO Cars VALUES(2,'Mercedes',57127);
 - INSERT INTO Cars VALUES(3,'Skoda',9000);
 - INSERT INTO Cars VALUES(4,'Volvo',29000);
 - INSERT INTO Cars VALUES(5,'Bentley',350000);
 - INSERT INTO Cars VALUES(6,'Citroen',21000);
 - INSERT INTO Cars VALUES(7,'Hummer',41400);
 - INSERT INTO Cars VALUES(8,'Volkswagen',21600);
 - COMMIT;
 - BEGIN TRANSACTION;
 - CREATE TABLE Orders(Id integer PRIMARY KEY, OrderPrice integer CHECK(OrderPrice>0),
 - Customer text);
 - INSERT INTO Orders(OrderPrice, Customer) VALUES(1200, "Williamson");
 - INSERT INTO Orders(OrderPrice, Customer) VALUES(200, "Robertson");
 - INSERT INTO Orders(OrderPrice, Customer) VALUES(40, "Robertson");
 - INSERT INTO Orders(OrderPrice, Customer) VALUES(1640, "Smith");
 - INSERT INTO Orders(OrderPrice, Customer) VALUES(100, "Robertson");
 - INSERT INTO Orders(OrderPrice, Customer) VALUES(50, "Williamson");
 - INSERT INTO Orders(OrderPrice, Customer) VALUES(150, "Smith");
 - INSERT INTO Orders(OrderPrice, Customer) VALUES(250, "Smith");
 - INSERT INTO Orders(OrderPrice, Customer) VALUES(840, "Brown");
 - INSERT INTO Orders(OrderPrice, Customer) VALUES(440, "Black");
 - INSERT INTO Orders(OrderPrice, Customer) VALUES(20, "Brown");
 - COMMIT;
 
然后在在終端執(zhí)行命令 .read data.sql,將數(shù)據(jù)導(dǎo)入到數(shù)據(jù)庫中:
- sqlite>
 - sqlite> .tables
 - Friends
 - sqlite> .read data.sql
 - sqlite> .tables
 - Cars Orders Teachers
 - sqlite>
 
可以看到,Cars 表和 Orders 表已經(jīng)導(dǎo)入到數(shù)據(jù)庫中,現(xiàn)在可以查詢了:
- sqlite>
 - sqlite> SELECT * FROM Cars;
 - Id Name Cost
 - ---- --------------- ---------------
 - 1 Audi 52642
 - 2 Mercedes 57127
 - 3 Skoda 9000
 - 4 Volvo 29000
 - 5 Bentley 350000
 - 6 Citroen 21000
 - 7 Hummer 41400
 - 8 Volkswagen 21600
 - sqlite> SELECT * FROM Orders;
 - Id OrderPrice Customer
 - ---- --------------- ---------------
 - 1 1200 Williamson
 - 2 200 Robertson
 - 3 40 Robertson
 - 4 1640 Smith
 - 5 100 Robertson
 - 6 50 Williamson
 - 7 150 Smith
 - 8 250 Smith
 - 9 840 Brown
 - 10 440 Black
 - 11 20 Brown
 - sqlite>
 
關(guān)于SQLite數(shù)據(jù)庫查找數(shù)據(jù)的知識就介紹到這里,我們還會在以后的文章里繼續(xù)介紹,謝謝各位一直以來的支持!
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