Unity&sqlite Database

SQLite is a cross-platform relational small database, very convenient, suitable for embedded devices, for the SQLite database, This database is formed in the form of a file (such as data.db); a database is made up of tables, where multiple tables can be stored in a database, and there is often a relationship between multiple tables.

For a table operation: Add and remove changes, statements and SQL Server statements, and in the table, there is a primary key (cannot be empty, can not be repeated, the addition of self-enhancement), foreign keys (and other tables associated), unique keys (unique can be empty, cannot be duplicated).

In the console, use SQLite's statement as follows:

Sqlite3 data.db; Open the database, no words to create a

. Table; View a few tables in the database

creat table USER (UID integer, name text, score integer); There are three fields in the CREATE TABLE table (can not write type, no type can be any type)

Insert into user values (1, ' Guo Jing ', 89)//Inserts a new piece of data into the user table

SELECT * from USER; View all content in the current table

drop table USER; Delete User table

CREATE table if not exists USER (UID Integer primary key autoincrement, name text, score integer); Integer UID self-increment

Insert into USER (name, score) VALUES (' Yang over ', 99); UID from Add data

Update USER set name= ' yellow old evil ' where score=89; Modify the artificial yellow and old evil of score to 89

Delete from USER; Delete all data

Delete from USER where uid = 1; Delete data with UID 1 in table

Select Uid,name,score from USER; Find content in a table

Select name from USER;

Select COUNT (*) from USER; Find a few rows of data in the user table

Select Sun (score) from USER; Look up all the score in the table and

Select AVG (score) from USER; Find the average number of score

SELECT * from USER where score>90 and score<95; Finding data in tables with score greater than 90 and less than 95

SELECT * from USER limit 2; Find the first two articles now

SELECT * Form USER ORDER BY score//Sort by score size order

Select *from USER order by score DECs; Sort in reverse order according to the size of score

Select User.Name, user.score,kungfu.name from User,kungfu where User.uid=kungfu.uid; Federated queries

. exit; Exit

SQLite is used in unity, you need to create a plugins folder in Project->assest, and then add the database in

The code is as follows:

Using system.collections;using system.collections.generic;using unityengine;using mono.data.sqlite;using System; public class Sqlitetext:monobehaviour {sqliteconnection con;//database connection class void Start () {//Connect to database, if not, create a database con = new Sqlitec Onnection ("Data Source =" + application.database + "/data/data.db"); con. Open ();//Opening database//Creating table String sqlstr= "CREATE table if not exist USER (UID Integer primary key autoincrement, name text, score I Nteger) "; Sqlitecommand command =new Sqlitecommand (Sqlstr,con);//Execution of commands (no queries, for additions and deletions) command. ExecuteNonQuery ()///Close command (since SQLite is single-threaded, the command should be closed after each execution of the command). Dispose ();//Insert Data SQLSTR = "INSERT into USER (Name,score) VALUES (' King Sledgehammer '," "); command. ExecuteNonQuery (sqlstr,con); command. Dispose (); sqlstr = "SELECT count (*) from USER";//Query single result and convert to int counts = Convert.ToInt32 (command). ExecuteScalar ()); command. Dispose ();//Query multiple results sqlitedatareader read result class Sqlstr = "select * from USER"; command = new Sqlitecommand (sqlstr, con); Sqlitedatareader reader = command. ExecuteReader ();//sQlitedatareader the logic of fetching data in a table//first, by default there is a pointer to the table header, there is a way to move the pointer down one line//and then get the corresponding value by the number of columns, then move the pointer down//read () read one line while (reader). Read ()) {//remove uidint uid = reader. GetInt32 (0);//Remove namestring name = Reader. GetString (1);//Get name//name = reader["name" in dictionary mode). ToString ();//Remove scorestring score = reader. GetInt32 (2);} Command. Dispose (); reader. Close ();} void Destroy () {con. Close ();//Shut down the database}}

　　

Unity&sqlite Database