Sqlite简单使用方法
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
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 */