iOS开发 - FMDB常用方法详解

实例化FMDatabase

//paths： ios下Document路径，Document为ios中可读写的文件夹，在Document中，可以通过打印沙盒路径查看数据库
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentDirectory = [paths objectAtIndex:0];

//dbPath： 数据库路径
NSString *dbPath = [documentDirectory stringByAppendingPathComponent:@"Test.db"];

//创建数据库实例 db ，如果路径中不存在"DB_NAME.db"的文件,sqlite会自动创建"DB_NAME.db"
FMDatabase *db= [FMDatabase databaseWithPath:dbPath] ;
if (![db open]) {
NSLog(@"数据库打开失败！！");
return ;
}

FMDB常用方法

#import <Foundation/Foundation.h>  
#import "FMDatabase.h"  
#import "FMDatabaseAdditions.h"  

@interface wiDBRoot : NSObject  
@property (retain, nonatomic) FMDatabase *DB;  
@property (retain, nonatomic) NSString *DBName;  

//+ (id)modelWithDBName:(NSString *)dbName;  
- (id)initWithDBName:(NSString *)dbName;  
// 删除数据库  
- (void)deleteDatabse;  

// 数据库存储路径  
//- (NSString *)getPath:(NSString *)dbName;  
// 打开数据库  
- (void)readyDatabse;  

// 判断是否存在表  
- (BOOL) isTableOK:(NSString *)tableName;  
// 获得表的数据条数  
- (BOOL) getTableItemCount:(NSString *)tableName;  
// 创建表  
- (BOOL) createTable:(NSString *)tableName withArguments:(NSString *)arguments;  
// 删除表-彻底删除表  
- (BOOL) deleteTable:(NSString *)tableName;  
// 清除表-清数据  
- (BOOL) eraseTable:(NSString *)tableName;  
// 插入数据  
- (BOOL)insertTable:(NSString*)sql, ...;  
// 修改数据  
- (BOOL)updateTable:(NSString*)sql, ...;  

// 整型  
- (NSInteger)getDb_Integerdata:(NSString *)tableName withFieldName:(NSString *)fieldName;  
// 布尔型  
- (BOOL)getDb_Booldata:(NSString *)tableName withFieldName:(NSString *)fieldName;  
// 字符串型  
- (NSString *)getDb_Stringdata:(NSString *)tableName withFieldName:(NSString *)fieldName;  
// 二进制数据型  
- (NSData *)getDb_Bolbdata:(NSString *)tableName withFieldName:(NSString *)fieldName;  

@end

FMDB常用方法的实现

// 数据库存储路径(内部使用)  
- (NSString *)getPath:(NSString *)dbName  
{  
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);  
    NSString *documentsDirectory = [paths objectAtIndex:0];  
    return [documentsDirectory stringByAppendingPathComponent:dbName];  
}  

// 打开数据库  
- (void)readyDatabse  
{        
    if ([DB databaseExists])  
        return;  

    //DB = [FMDatabase databaseWithPath:DBName];  
    DB = [[FMDatabase alloc] initWithPath:DBName];  

    if (![DB open])  
    {  
        [DB close];  
        NSAssert1(0, @"Failed to open database file with message '%@'.", [DB lastErrorMessage]);  
    }  

    // kind of experimentalish.  
    [DB setShouldCacheStatements:YES];  
}  

// 删除数据库  
- (void)deleteDatabse  
{  
    BOOL success;  
    NSError *error;  

    NSFileManager *fileManager = [NSFileManager defaultManager];  

    // delete the old db.  
    if ([fileManager fileExistsAtPath:DBName])  
    {  
        [DB close];  
        success = [fileManager removeItemAtPath:DBName error:&error];  
        if (!success) {  
            NSAssert1(0, @"Failed to delete old database file with message '%@'.", [error localizedDescription]);  
        }  
    }      
}  

// 判断是否存在表  
- (BOOL) isTableOK:(NSString *)tableName  
{  
    FMResultSet *rs = [DB executeQuery:@"SELECT count(*) as 'count' FROM sqlite_master WHERE type ='table' and name = ?", tableName];  
    while ([rs next])  
    {  
        // just print out what we've got in a number of formats.  
        NSInteger count = [rs intForColumn:@"count"];  
        WILog(@"isTableOK %d", count);  

        if (0 == count)  
        {  
            return NO;  
        }  
        else  
        {  
            return YES;  
        }  
    }  

    return NO;  
}  

// 获得表的数据条数  
- (BOOL) getTableItemCount:(NSString *)tableName  
{  
    NSString *sqlstr = [NSString stringWithFormat:@"SELECT count(*) as 'count' FROM %@", tableName];  
    FMResultSet *rs = [DB executeQuery:sqlstr];  
    while ([rs next])  
    {  
        NSInteger count = [rs intForColumn:@"count"];  
        WILog(@"TableItemCount %d", count);  

        return count;  
    }  

    return 0;  
}  

// 创建表  
- (BOOL) createTable:(NSString *)tableName withArguments:(NSString *)arguments  
{  
    NSString *sqlstr = [NSString stringWithFormat:@"CREATE TABLE %@ (%@)", tableName, arguments];  
    if (![DB executeUpdate:sqlstr])  
    {  
        WILog(@"Create db error!");  
        return NO;  
    }  

    return YES;  
}  

// 删除表  
- (BOOL) deleteTable:(NSString *)tableName  
{  
    NSString *sqlstr = [NSString stringWithFormat:@"DROP TABLE %@", tableName];  
    if (![DB executeUpdate:sqlstr])  
    {  
        WILog(@"Delete table error!");  
        return NO;  
    }  

    return YES;  
}  

// 清除表  
- (BOOL) eraseTable:(NSString *)tableName  
{  
    NSString *sqlstr = [NSString stringWithFormat:@"DELETE FROM %@", tableName];  
    if (![DB executeUpdate:sqlstr])  
    {  
        WILog(@"Erase table error!");  
        return NO;  
        }  

    return YES;  
    }      

// 插入数据  
- (BOOL)insertTable:(NSString*)sql, ...  
{  
    va_list args;  
    va_start(args, sql);  

    BOOL result = [DB executeUpdate:sql error:nil withArgumentsInArray:nil orVAList:args];  

    va_end(args);  
    return result;  
}  

// 修改数据  
- (BOOL)updateTable:(NSString*)sql, ...  
{  
    va_list args;  
    va_start(args, sql);  

    BOOL result = [DB executeUpdate:sql error:nil withArgumentsInArray:nil orVAList:args];  

    va_end(args);  
    return result;  
}  

// 整型  
- (NSInteger)getDb_Integerdata:(NSString *)tableName withFieldName:(NSString *)fieldName  
{  
    NSInteger result = NO;  

    NSString *sql = [NSString stringWithFormat:@"SELECT %@ FROM %@", fieldName, tableName];  
    FMResultSet *rs = [DB executeQuery:sql];  
    if ([rs next])  
        result = [rs intForColumnIndex:0];  
    [rs close];  

    return result;  
}  

// 布尔型  
- (BOOL)getDb_Booldata:(NSString *)tableName withFieldName:(NSString *)fieldName  
{  
    BOOL result;  

    result = [self getDb_Integerdata:tableName withFieldName:fieldName];  

    return result;  
}  

// 字符串型  
- (NSString *)getDb_Stringdata:(NSString *)tableName withFieldName:(NSString *)fieldName  
{  
    NSString *result = NO;  

    NSString *sql = [NSString stringWithFormat:@"SELECT %@ FROM %@", fieldName, tableName];  
    FMResultSet *rs = [DB executeQuery:sql];  
    if ([rs next])  
        result = [rs stringForColumnIndex:0];  
    [rs close];  

    return result;  
}  

// 二进制数据型  
- (NSData *)getDb_Bolbdata:(NSString *)tableName withFieldName:(NSString *)fieldName  
{  
    NSData *result = NO;  

    NSString *sql = [NSString stringWithFormat:@"SELECT %@ FROM %@", fieldName, tableName];  
    FMResultSet *rs = [DB executeQuery:sql];  
    if ([rs next])  
        result = [rs dataForColumnIndex:0];  
    [rs close];  

    return result;  
}  

- (void)dealloc {  
    [DB close];  
    [DB release];  
    [DBName release];  
    [super dealloc];  
}  

@end