Home  >  Article  >  Database  >  Sqlite简单使用方法

Sqlite简单使用方法

WBOY
WBOYOriginal
2016-06-07 14:59:001941browse

Sqlite简单使用方法 1.首先要添加 libsqlite3.dylib 库。在添加库的时候,你会发现有个libsqlite3.dylib 还有一个 libsqlite3.0.dylib。这样你就会疑问,两个的区别。这里介绍一下:实际上libsqlite3.dylib本身是个链接,它指向了libsqlite3.0.dylib。libsql

Sqlite简单使用方法

 

1.首先要添加 libsqlite3.dylib 库。在添加库的时候,你会发现有个libsqlite3.dylib 还有一个 libsqlite3.0.dylib。这样你就会疑问,两个的区别。这里介绍一下:实际上libsqlite3.dylib本身是个链接,它指向了libsqlite3.0.dylib。libsqlite3.dylib总是指向最新的sqlite动态库。

 

2.在view中引入框架(2种方法)。

 

 (1)#import    (2)#import"/usr/include/sqlite3.h"  

  sqlite3 *database;

3.sqlite数据库是文件数据库,是保存在文件系统中的。在Documents下创建数据库(路径)。

 

    NSArray *documentsPath =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);

   NSString *databaseFilePath = [[documentsPathobjectAtIndex:0]stringByAppendingPathComponent:@"mydb"];

4.打开数据库

    if (sqlite3_open([databaseFilePathUTF8String], &database) ==SQLITE_OK) {

        NSLog(@"open sqlite db ok.");

    }

5.建表语句

    char *errorMsg;

    constchar *createSql ="create table if not exists persons(id integer primary key autoincrement, name text)";

   if (sqlite3_exec(database, createSql,NULL,NULL, &errorMsg) ==SQLITE_OK) {

        NSLog(@"create ok");

    }

6.向表中插入记录

    const char *insertSql ="insert into persons (name) values ('zhangsan')";

   if (sqlite3_exec(database, insertSql,NULL,NULL, &errorMsg) ==SQLITE_OK) {

        NSLog(@"insert ok.");

    }else{

       NSLog(@"error:%s",errorMsg);

       sqlite3_free(errorMsg);

    }

7.查询结果

    const char *selectSql ="select id,name from persons";

   sqlite3_stmt *statement;  

    if (sqlite3_prepare_v2(database, selectSql, -1, &statement, nil) == SQLITE_OK) {

        NSLog(@"select ok");

       while (sqlite3_step(statement) ==SQLITE_ROW) {

           int _id =sqlite3_column_int(statement,0);

            

           char *name = (char*)sqlite3_column_text(statement,1);

           NSString *nsAddressStr = [[NSStringalloc]initWithUTF8String:name];

            

           NSLog(@"id:%i  name:%@",_id,nsAddressStr);

        }

    }

8.关闭数据库

    sqlite3_close(database);

 

sqlite3 *database;数据库句柄

sqlite3_stmt    用于保存编译好的sql语句

sqlite3_open()  打开数据库,没有的时候创建数据库

sqlite3_exec()  执行非查询的sql语句

sqlite3_prepare() 准备sql语句,执行select语句

sqlite3_step()  再调用sqlite3_prepare后,使用这个函数在记录集中移动

sqlite3_finalize() 释放sql资源

sqlite3_close() 关闭数据库

 

sqlite3_bind_int(stmt,1,1);  //绑定第一个int参数

sqlite3_bind_text(stmt,2,[? UTF8String],-1,SQLITE_TRANSIENT);//绑定第二个字符串参数

 

记录集中获取字段

sqlite3_column_int()  取int类型数据

sqlite3_column_text() 取text型数据

sqlite3_column_blob() 取blob型数据

 

 

#define SQLITE_OK           0   /* Successful result */

/* beginning-of-error-codes */

#define SQLITE_ERROR        1   /* SQL error or missing database */

#define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */

#define SQLITE_PERM         3   /* Access permission denied */

#define SQLITE_ABORT        4   /* Callback routine requested an abort */

#define SQLITE_BUSY         5   /* The database file is locked */

#define SQLITE_LOCKED       6   /* A table in the database is locked */

#define SQLITE_NOMEM        7   /* A malloc() failed */

#define SQLITE_READONLY     8   /* Attempt to write a readonly database */

#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/

#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */

#define SQLITE_CORRUPT     11   /* The database disk image is malformed */

#define SQLITE_NOTFOUND    12   /* NOT USED. Table or record not found */

#define SQLITE_FULL        13   /* Insertion failed because database is full */

#define SQLITE_CANTOPEN    14   /* Unable to open the database file */

#define SQLITE_PROTOCOL    15   /* NOT USED. Database lock protocol error */

#define SQLITE_EMPTY       16   /* Database is empty */

#define SQLITE_SCHEMA      17   /* The database schema changed */

#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */

#define SQLITE_CONSTRAINT  19   /* Abort due to constraint violation */

#define SQLITE_MISMATCH    20   /* Data type mismatch */

#define SQLITE_MISUSE      21   /* Library used incorrectly */

#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */

#define SQLITE_AUTH        23   /* Authorization denied */

#define SQLITE_FORMAT      24   /* Auxiliary database format error */

#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */

#define SQLITE_NOTADB      26   /* File opened that is not a database file */

#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */

#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */ 

 

当调用 sqlite3_prepare_v2() 函数的时候,是一个将SQL语句编译为sqlite内部一个结构体(sqlite3_stmt).

 

该结构体中包含了将要执行的的SQL语句的信息.

 

通常情况下,应该是返回0。还有一些时候是返回其他数值。

 

我以1为例,简单介绍一下错误解决的思路和方法:

 

 #define SQLITE_ERROR        1   /* SQL error or missing database */

 

Statement:
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn