Objective-c简单操作SQLite

//
//  LSQLiteDB.m
//  lua-hello
//
//  Created by leiwuluan on 14-2-13.
//  Copyright (c) 2014年 hello. All rights reserved.
//

#import "LSQLiteDB.h"
#import "NSStringExtend.h"
#import "NSDataAdditions.h"
#import "NSURLAdditions.h"

@implementation LSQLiteDB

// 打开 或 创建一个数据库
- (int) openDBByDBName: (NSString *) _DBName {
NSArray *documentsPaths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *databaseFilePath=[[documentsPaths objectAtIndex:0] stringByAppendingPathComponent: _DBName];

if (sqlite3_open([databaseFilePath UTF8String], &database)==SQLITE_OK) {

// 创建一个缓存表
NSString *_sql = @"create table if not exists dataCache (dkey varchar(100) PRIMARY KEY, dvalue TEXT, ctype INTEGER, utime timestamp)";

char *errorMsg;
if (sqlite3_exec(database, [_sql UTF8String], NULL, NULL, &errorMsg)==SQLITE_OK) {
NSLog(@"Create dataCache Success.");
}else {
NSLog(@"Create dataCache Failure %s",errorMsg);
}

NSLog(@"SQLites is opened.");
return YES;
}else {
NSLog(@"SQLites open Error.");
return NO;
}

}

// 执行一条slq
- (int) execBySql: (NSString *) _sql {
// create table if not exists dataCache (dkey varchar(100) PRIMARY KEY, dvalue TEXT, utime timestamp)

char *errorMsg;
if (sqlite3_exec(database, [_sql UTF8String], NULL, NULL, &errorMsg)==SQLITE_OK) {
NSLog(@"Create Success.");
return YES;
}else {
NSLog(@"Create Failure %s",errorMsg);
return NO;
}
}

// 通过键值更新
- (int) updateRowData:(NSString *) _rowData forKey: (NSString *) _key ctype: (NSInteger) _ctype {

_rowData = [_rowData stringByReplacingOccurrencesOfString:@"'" withString:@"‘"];
NSString *_sql = [NSString stringWithFormat:@"INSERT OR REPLACE INTO dataCache(dkey, dvalue, utime, ctype) values('%@', '%@', datetime('now'), %d)", _key, _rowData, _ctype];
char *errorMsg;
if (sqlite3_exec(database, [_sql UTF8String], NULL, NULL, &errorMsg)==SQLITE_OK) {
NSLog(@"Insert Success.");
return YES;
}else {
NSLog(@"Insert Failure %s, |%@",errorMsg , _sql);
return NO;
}

}

// 缓存获取值
- (NSString *) findRowDataForKey: (NSString *) _key {
NSString *query = [NSString stringWithFormat:@"select dvalue from dataCache where dkey='%@'", _key];
sqlite3_stmt *statement;
if (sqlite3_prepare_v2(database, [query UTF8String], -1, &statement, nil) == SQLITE_OK) {
if (sqlite3_step(statement) == SQLITE_ROW) {
//get data
char *dvalue = (char *)sqlite3_column_text(statement, 0);
NSString *retDvalue = [NSString stringWithCString:dvalue encoding:NSUTF8StringEncoding];

return retDvalue;
}
sqlite3_finalize(statement);
}
return nil;
}

// 清除过期数据
- (int) clearCAData: (NSString *) cacheDate {
NSString *_sql = [NSString stringWithFormat:@"delete from dataCache where ctype = 1 and utime < '%@'", cacheDate];
char *errorMsg;
if (sqlite3_exec(database, [_sql UTF8String], NULL, NULL, &errorMsg)==SQLITE_OK) {
NSLog(@"Insert Success.");
return YES;
}else {
NSLog(@"Insert Failure %s, |%@",errorMsg , _sql);
return NO;
}
}

// 关闭数据库
-(int) closeDatabase {
sqlite3_close(database);
return YES;
}

-(void) dealloc{
[super dealloc];
[self closeDatabase];
}

-(NSMutableArray*) queryBySQL:(NSString *) sql
{
NSMutableArray *result = [[NSMutableArray alloc]init];
sqlite3_stmt *stmt;
if (sqlite3_prepare_v2(database, [sql UTF8String], -1, &stmt, nil) == SQLITE_OK) {
//        int num_cols = sqlite3_data_count(stmt);
while (sqlite3_step(stmt)==SQLITE_ROW) {
int num_cols = sqlite3_column_count(stmt);
NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithCapacity:num_cols];
if (num_cols > 0) {
int i;
for (i = 0; i < num_cols; i++) {
const char *col_name = sqlite3_column_name(stmt, i);
if (col_name) {
NSString *colName = [NSString stringWithUTF8String:col_name];
id value = nil;
// fetch according to type
switch (sqlite3_column_type(stmt, i)) {
case SQLITE_INTEGER: {
int i_value = sqlite3_column_int(stmt, i);
value = [NSNumber numberWithInt:i_value];
break;
}
case SQLITE_FLOAT: {
double d_value = sqlite3_column_double(stmt, i);
value = [NSNumber numberWithDouble:d_value];
break;
}
case SQLITE_TEXT: {
char *c_value = (char *)sqlite3_column_text(stmt, i);
value = [[NSString alloc] initWithUTF8String:c_value];
break;
}
case SQLITE_BLOB: {
value = sqlite3_column_blob(stmt, i);
break;
}
}
// save to dict
if (value) {
[dict setObject:value forKey:colName];
}
}
}
}
[result addObject:dict];
}
/*
while (sqlite3_step(stmt)==SQLITE_ROW) {
char *name = (char *)sqlite3_column_text(stmt, 1);
NSString *nameString = [[NSString alloc] initWithUTF8String:name];
NSLog(@"%@", nameString);
}*/
sqlite3_finalize(stmt);
}
return result;
}

// 判断表是否存在
-(int) tableIsExists:(NSString*) tableName
{
NSString *sql = [NSString stringWithFormat:@"SELECT count(*) as count_num FROM sqlite_master WHERE type=\"table\" AND name = \"%@\"", tableName ];
NSMutableArray *arr = [self queryBySQL: sql];
NSMutableDictionary *dic = [arr objectAtIndex:0];
return (int)[dic valueForKey:@"count_num"];
}
@end