您好，我正在使用以下代码在应用程序中实现 SQLite 数据库。朋友们还有其他最简单的方法来实现这一点，它适用于 SQLite 数据库的所有内容。
// .h File of DBManager
#import <Foundation/Foundation.h>
#import <sqlite3.h>
@interface DBOperation : NSObject
{
}
+(void)OpenDatabase:(NSString*)path; //Open the Database
//+(void)finalizeStatements;//Closing and do the final statement at application exits
+(void)checkCreateDB;
//+(int) getLastInsertId;
+(BOOL) executeSQL:(NSString *)sqlTmp;
+(NSMutableArray*) selectData:(NSString *)sql;
@end
//
// DBOperation.m
// Puzzle
//
// Created by hbmac1 on 9/22/09.
// Copyright 2009 __MyCompanyName__. All rights reserved.
//
#import "DBOperation.h"
static sqlite3 *database = nil;
static int conn;
@implementation DBOperation
+(void)checkCreateDB
{
@try {
NSString *dbPath,*databaseName;
databaseName=@"pointtable.sqlite";
NSArray *docPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
NSString *docDir = [docPaths objectAtIndex:0];
dbPath = [docDir stringByAppendingPathComponent:databaseName];
BOOL success;
NSFileManager *fm = [NSFileManager defaultManager];
success=[fm fileExistsAtPath:dbPath];
if(success)
{
[self OpenDatabase:dbPath];
return;
}
NSString *dbPathFromApp=[[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:databaseName];
[fm copyItemAtPath:dbPathFromApp toPath:dbPath error:nil];
[self OpenDatabase:dbPath];
}
@catch (NSException *exception) {
NSLog(@"%@",[exception reason]);
}
}
//Open database
+ (void) OpenDatabase:(NSString*)path
{
@try
{
conn = sqlite3_open([path UTF8String], &database);
if (conn == SQLITE_OK) {
}
else
sqlite3_close(database); //Even though the open call failed, close the database connection to release all the memory.
}
@catch (NSException *e) {
NSLog(@"%@",e);
}
}
+(NSMutableArray*) selectData:(NSString *)sql
{
@try
{
if (conn == SQLITE_OK)
{
sqlite3_stmt *stmt = nil;
if(sqlite3_prepare_v2(database, [sql UTF8String], -1, &stmt, NULL) != SQLITE_OK) {
[NSException raise:@"DatabaseException" format:@"Error while creating statement. '%s'", sqlite3_errmsg(database)];
}
NSMutableArray *obj = [[NSMutableArray alloc]init];
int numResultColumns = 0;
while (sqlite3_step(stmt) == SQLITE_ROW) {
numResultColumns = sqlite3_column_count(stmt);
@autoreleasepool {
NSMutableDictionary *tmpObj = [[NSMutableDictionary alloc]init];
for(int i = 0; i < numResultColumns; i++){
if(sqlite3_column_type(stmt, i) == SQLITE_INTEGER){
const char *name = sqlite3_column_name(stmt, i);
NSString *columnName = [[NSString alloc]initWithCString:name encoding:NSUTF8StringEncoding];
[tmpObj setObject:[NSString stringWithFormat:@"%i",sqlite3_column_int(stmt, i)] forKey:columnName];
} else if (sqlite3_column_type(stmt, i) == SQLITE_FLOAT) {
const char *name = sqlite3_column_name(stmt, i);
NSString *columnName = [[NSString alloc]initWithCString:name encoding:NSUTF8StringEncoding];
[tmpObj setObject:[NSString stringWithFormat:@"%f",sqlite3_column_double(stmt, i)] forKey:columnName];
} else if (sqlite3_column_type(stmt, i) == SQLITE_TEXT) {
const char *name = sqlite3_column_name(stmt, i);
NSString *tmpStr = [NSString stringWithUTF8String:(char *)sqlite3_column_text(stmt, i)];
if ( tmpStr == nil) {
tmpStr = @"";
}
NSString *columnName = [[NSString alloc]initWithCString:name encoding:NSUTF8StringEncoding];
[tmpObj setObject:tmpStr forKey:columnName];
} else if (sqlite3_column_type(stmt, i) == SQLITE_BLOB) {
}
else if (sqlite3_column_type(stmt, i) == SQLITE_NULL) {
const char *name = sqlite3_column_name(stmt, i);
NSString *tmpStr = @"";
NSString *columnName = [[NSString alloc]initWithCString:name encoding:NSUTF8StringEncoding];
[tmpObj setObject:tmpStr forKey:columnName];
}
}
[obj addObject:tmpObj];
}
}
return obj;
} else {
return nil;
}
}
@catch (NSException *exception) {
NSLog(@"%@",[exception reason]);
return nil;
}
}
+(BOOL) executeSQL:(NSString *)sqlTmp {
@try {
if(conn == SQLITE_OK) {
const char *sqlStmt = [sqlTmp cStringUsingEncoding:NSUTF8StringEncoding];
sqlite3_stmt *cmp_sqlStmt1;
int returnValue = sqlite3_prepare_v2(database, sqlStmt, -1, &cmp_sqlStmt1, NULL);
returnValue == SQLITE_OK ? NSLog(@"\n Inserted \n") :NSLog(@"\n Not Inserted \n");
sqlite3_step(cmp_sqlStmt1);
sqlite3_finalize(cmp_sqlStmt1);
if (returnValue == SQLITE_OK)
{
return TRUE;
}
}
return FALSE;
}
@catch (NSException *exception) {
NSLog(@"%@",[exception reason]);
return NO;
}
}
@end