iOS，SQLite

SQLIte是一个轻量级的数据库，占用内存小，在iOS开发中，如果要做一些缓存数据的处理，有时候就考虑要用到SQLIte了。

亲测有效。拿来直接用。

在写代码前注意加上libsqlite3.tdb

下面直接上代码：

<pre name="code" class="objc">#import "JYSqlite.h"#import "sqlite3.h"#import "YSPattern.h"@interface JYSqlite(){    //声明一个sqlite3的数据库    sqlite3 *db;}@end@implementation JYSqlite//返回数据库在文件夹中的全路径信息-(NSString *)filePath{    NSArray *paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    NSString *documentDir=[paths objectAtIndex:0];    //NSLog(@"我看看路径%@",documentDir);    return [documentDir stringByAppendingPathComponent:@"/patternTest.sqlite"];}//打开数据库的方法-(void)openDB{    if(sqlite3_open([[self filePath]UTF8String], &db)!=SQLITE_OK)    {        sqlite3_close(db);        //NSLog(@"数据库打开失败");    }   // NSLog(@"数据库打开成功");}//创建表-(void)createTable{    //模式名称，模式描述，模式图片    NSString *sql=@"create TABLE if not EXISTS patternTable(name NSString,desc NSString,img NSString,rValue NSString,gValue NSString,bValue NSString);";    char *errorMesg=NULL;    int result=sqlite3_exec(db, [sql UTF8String], NULL, NULL, &errorMesg);    if(result==SQLITE_OK)    {        NSLog(@"创建模式表成功");    }    else    {        NSLog(@"创建模式表失败%s",errorMesg);    }}//插入数据的方法-(void)insertRecordIntoTableName:(NSString *)tableName                      withField1:(NSString *)field1 field1Value:(NSString *)field1Value                       andField2:(NSString *)field2 field2Value:(NSString *)field2Value                       andField3:(NSString *)field3 field3Value:(NSString *)field3Value                       andField4:(NSString *)field4 field4Value:(NSString *)field4Value                       andField5:(NSString *)field5 field5Value:(NSString *)field5Value                       andField6:(NSString *)field6 field6Value:(NSString *)field6Value{    NSString *sql=[NSString stringWithFormat:@"INSERT INTO '%@'('%@','%@','%@','%@','%@','%@') VALUES('%@','%@','%@','%@','%@','%@')",tableName,field1,field2,field3,field4,field5,field6,field1Value,field2Value,field3Value,field4Value,field5Value,field6Value];    char *err;    if(sqlite3_exec(db, [sql UTF8String], NULL, NULL, &err)!=SQLITE_OK)    {        sqlite3_close(db);        NSAssert(0,@"插入数据错误！");    }    }//删除数据-(void)deleteRecordWithName:(NSString *)patternName{    sqlite3_stmt *stmt;    NSString *sql = [NSString stringWithFormat:@"delete from patternTable where name = '%@'", patternName];        if (sqlite3_prepare_v2(db, [sql UTF8String], -1, &stmt, nil) == SQLITE_OK)    {        sqlite3_step(stmt);        //觉的应加一个判断, 若有这一行则删除        if (sqlite3_step(stmt) == SQLITE_DONE)        {            sqlite3_finalize(stmt);                    }    }}//更新rgb-(void)updateRecordByRGB:(NSString *)patternName rValue:(NSString *)rValue gValue:(NSString *)gValue bValue:(NSString *)bValue{    sqlite3_stmt *stmt = nil;    NSString *sql = [NSString stringWithFormat:@"update patternTable set rValue = '%@',gValue='%@',bValue='%@'  where name = '%@'", rValue,gValue,bValue,patternName];        NSLog(@"===%@",sql);        if (sqlite3_prepare_v2(db, [sql UTF8String], -1, &stmt, NULL) == SQLITE_OK)    {        if (sqlite3_step(stmt) == SQLITE_ROW)        {            //觉的应加一个判断, 若有这一行则修改            if (sqlite3_step(stmt) == SQLITE_DONE)            {                sqlite3_finalize(stmt);            }        }    }}//更新模式名称,模式描述,背景图标识-(void)updateRecordByOldPatternName:(NSString *)oldPatternName andNewPatternName:(NSString *)newPatternName andDesc:(NSString *)descLabel andImg:(NSString *)imgKey{    sqlite3_stmt *stmt = nil;    NSString *sql = [NSString stringWithFormat:@"update patternTable set name = '%@',desc='%@',img='%@'  where name = '%@'", newPatternName,descLabel,imgKey,oldPatternName];        //NSLog(@"===%@",sql);        if (sqlite3_prepare_v2(db, [sql UTF8String], -1, &stmt, NULL) == SQLITE_OK)    {        if (sqlite3_step(stmt) == SQLITE_ROW)        {            //觉的应加一个判断, 若有这一行则修改            if (sqlite3_step(stmt) == SQLITE_DONE)            {                sqlite3_finalize(stmt);            }        }    }    }//查询数据-(void)getAllRecord{    //NSLog(@"***************查询所有数据********************");    NSString *sql=@"SELECT * FROM patternTable";    sqlite3_stmt *statement;        if(sqlite3_prepare_v2(db, [sql UTF8String], -1, &statement, nil)==SQLITE_OK)    {        while (sqlite3_step(statement)==SQLITE_ROW)        {            char *name=(char *)sqlite3_column_text(statement, 0);            NSString *patternName=[[NSString alloc]initWithUTF8String:name];                        char *desc=(char *)sqlite3_column_text(statement, 1);            NSString *descLabel=[[NSString alloc]initWithUTF8String:desc];                        char *img=(char *)sqlite3_column_text(statement, 2);            NSString *imgKey=[[NSString alloc]initWithUTF8String:img];                        char *r =(char *)sqlite3_column_text(statement, 3);            NSString *rValue=[[NSString alloc]initWithUTF8String:r];                        char *g =(char *)sqlite3_column_text(statement, 4);            NSString *gValue=[[NSString alloc]initWithUTF8String:g];                        char *b =(char *)sqlite3_column_text(statement, 5);            NSString *bValue=[[NSString alloc]initWithUTF8String:b];                        YSPattern *pattern=[[YSPattern alloc]init];            pattern.patternName=patternName;            pattern.descLabel=descLabel;            pattern.imgKey=imgKey;            pattern.rValue=rValue;            pattern.gValue=gValue;            pattern.bValue=bValue;            NSLog(@"====%@",pattern.patternName);                        [self.patterns addObject:pattern];        }       // NSLog(@"==%ld",self.patterns.count);    }}@end