我是iphone上sqlite的新手。
我要使用terminal创建数据库。现在我需要在我的应用程序中通过代码创建一个表。
我的代码是
-(BOOL)createtable:(NSString *)tableName {
BOOL ret;
int rc;
// SQL to create new table
NSString *sql_str = [NSString stringWithFormat:@"CREATE TABLE %@ (pk INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL , ItemName VARCHAR(100), Quantity INTEGER DEFAULT 0, Status BOOLEAN,Type VARCHAR(100))", tableName];
const char *sqlStatement = (char *)[sql_str UTF8String];
NSLog(@"query %s",sqlStatement);
sqlite3_stmt *stmt;
rc = sqlite3_prepare_v2(database, sqlStatement, -1, &stmt, NULL);
ret = (rc == SQLITE_OK);
if (ret)
{ // statement built, execute
rc = sqlite3_step(stmt);
ret = (rc == SQLITE_DONE);
}
sqlite3_finalize(stmt); // free statement
NSLog(@"creating table");
return ret;
}
但是没有创建表，我在mozilla sqlite manager中检查该数据库。
任何人都可以帮助我。
提前感谢你。
答案 0 :(得分：15)
您可以使用sqlite3_exec（）方法代替sqlite3_step（）。
sqlite3_exec（）将执行您提供的任何查询。
我相信，这肯定对你有帮助。
-(BOOL)createNewTable
{
NSArray *array=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *filePath=[array objectAtIndex:0];
filePath =[filePath stringByAppendingPathComponent:@"yourdatabase.db"];
NSFileManager *manager=[NSFileManager defaultManager];
BOOL success = NO;
if ([manager fileExistsAtPath:filePath])
{
success =YES;
}
if (!success)
{
NSString *path2=[[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"yourdatabase.db"];
success =[manager copyItemAtPath:path2 toPath:filePath error:nil];
}
createStmt = nil;
NSString *tableName=@"SecondTable";
if (sqlite3_open([filePath UTF8String], &database) == SQLITE_OK) {
if (createStmt == nil) {
NSString *query=[NSString stringWithFormat:@"create table %@(rollNo integer, name text)",tableName];
if (sqlite3_prepare_v2(database, [query UTF8String], -1, &createStmt, NULL) != SQLITE_OK) {
return NO;
}
sqlite3_exec(database, [query UTF8String], NULL, NULL, NULL);
return YES;
}
}
return YES;
}
答案 1 :(得分：1)
我也发布了一个答案，因为您的示例中没有错误处理，这似乎很有价值
INIT DB：
self.databasePath = [[NSString alloc]init];
BOOL success;
NSFileManager *fileManager = [NSFileManager defaultManager];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:@"myDB.db"];
success = [fileManager fileExistsAtPath:writableDBPath];
self.databasePath = writableDBPath;
NSFileManager *filemgr = [NSFileManager defaultManager];
if ([filemgr fileExistsAtPath: self.databasePath ] == NO)
{
const char *dbpath = [self.databasePath UTF8String];
if (sqlite3_open(dbpath, &myDB) == SQLITE_OK)
{
NSLog(@"Database Opened");
sqlite3_close(myDB);
} else {
NSLog(@"Failed to open/create database");
}
}else {
// NSLog(@"File exist");
}
打电话来创建表：
const char *dbpath = [self.databasePath UTF8String];
if (sqlite3_open(dbpath, &myDB) == SQLITE_OK) {
NSString *charsTableNameQuery = [NSString stringWithFormat:@"CREATE TABLE IF NOT EXISTS %@(id INTEGER PRIMARY KEY, charName TEXT)",charsTableName];
int results = 0;
//create all chars tables
const char *charsTableNameQuerySQL = [charsTableNameQuery UTF8String];
sqlite3_stmt * charsTableNameStatment = nil;
results = sqlite3_exec(myDB, charsTableNameQuerySQL, NULL, NULL, NULL);
if (results != SQLITE_DONE) {
const char *err = sqlite3_errmsg(tekkenDB);
NSString *errMsg = [NSString stringWithFormat:@"%s",err];
if (![errMsg isEqualToString:@"not an error"]) {
NSLog(@"createTables-chartables error: %@",errMsg);
return FALSE;
}
}
sqlite3_finalize(charsTableNameStatment);
sqlite3_close(myDB);
return TRUE;
}else{
NSLog(@"database not opened");
}
return FALSE;
}
答案 2 :(得分：0)
致电接收内存警告
(IBAction)findContact:(UIButton *)sender {
const char *dbPath = [databasePath UTF8String];
sqlite3_stmt *statement;
if (sqlite3_open(dbPath, &contactDB)== SQLITE_OK) {
NSString *querySQL = [NSString stringWithFormat:@"SELECT ADDRESS,PHONE FROM CONTACTS WHERE NAME = \"%@\"",_name.text];
const char *query_stmt = [querySQL UTF8String];
if(sqlite3_prepare_v2(contactDB, query_stmt, -1, &statement, NULL)== SQLITE_OK)
{
if (sqlite3_step(statement)== SQLITE_ROW) {
NSString *addressField = [[NSString alloc]initWithUTF8String:(const char *) sqlite3_column_text(statement, 0)];
_address.text = addressField;
NSString *phoneField = [[NSString alloc]initWithUTF8String:(const char *) sqlite3_column_text(statement, 1)];
_phoneNo.text = phoneField;
_status.text = @"Match Found";
}else{
_status.text = @"Match not found";
_address.text = @"";
_phoneNo.text = @"";
}
sqlite3_finalize(statement);
}
sqlite3_close(contactDB);
}
}
答案 3 :(得分：0)
将此代码粘贴到CustomDB.m文件中。 （＆＃34; CustomDB.m＆＃34;＆lt; - 这是我的文件名）
#import "CustomDB.h"
@implementation CustomDB
- (void)createWith:(NSString *)strFileName;
{
NSArray *path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docPath = [path objectAtIndex:0];
dbPathString = [docPath stringByAppendingPathComponent:strFileName];
NSLog(@"%@",dbPathString);
char *error;
NSFileManager *fileManager = [NSFileManager defaultManager];
if (![fileManager fileExistsAtPath:dbPathString]) {
const char *dbPath = [dbPathString UTF8String];
//creat db here
if (sqlite3_open(dbPath, &personDB)==SQLITE_OK) {
const char *sql_stmt = "CREATE TABLE IF NOT EXISTS PERSONS (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, AGE TEXT)";
sqlite3_exec(personDB, sql_stmt, NULL, NULL, &error);
sqlite3_close(personDB);
}
}
}
-(void)insertInToDB:(NSString *)strQuery{
char *error;
if (sqlite3_open([dbPathString UTF8String], &personDB)==SQLITE_OK) {
NSString *inserStmt = [NSString stringWithFormat:@"%@", strQuery];
const char *insert_stmt = [inserStmt UTF8String];
if (sqlite3_exec(personDB, insert_stmt, NULL, NULL, &error)==SQLITE_OK) {
NSLog(@"Insert successfully");
}
sqlite3_close(personDB);
}
}
-(NSArray *)selectFromDB:(NSString *)strQuery{
sqlite3_stmt *statement;
id result;
NSMutableArray *thisArray = [[NSMutableArray alloc]init];
if (sqlite3_open([dbPathString UTF8String], &personDB)==SQLITE_OK) {
NSString *querySql = [NSString stringWithFormat:@"SELECT * FROM PERSONS"];
const char* query_sql = [querySql UTF8String];
if (sqlite3_prepare(personDB, query_sql, -1, &statement, NULL)==SQLITE_OK) {
while (sqlite3_step(statement)==SQLITE_ROW) {
NSMutableDictionary *thisDict = [[NSMutableDictionary alloc]init];
for (int i = 0 ; i < sqlite3_column_count(statement) ; i++) {
if(sqlite3_column_type(statement,i) == SQLITE_NULL){
continue;
}
if (sqlite3_column_decltype(statement,i) != NULL &&
strcasecmp(sqlite3_column_decltype(statement,i),"Boolean") == 0) {
result = [NSNumber numberWithBool:(BOOL)sqlite3_column_int(statement,i)];
} else if (sqlite3_column_type(statement,i) == SQLITE_INTEGER) {
result = [NSNumber numberWithInt:(int)sqlite3_column_int(statement,i)];
} else if (sqlite3_column_type(statement,i) == SQLITE_FLOAT) {
result = [NSNumber numberWithFloat:(float)sqlite3_column_double(statement,i)];
} else {
if((char *)sqlite3_column_text(statement,i) != NULL){
result = [[NSString alloc] initWithUTF8String:(char *)sqlite3_column_text(statement,i)];
[thisDict setObject:result
forKey:[NSString stringWithUTF8String:sqlite3_column_name(statement,i)]];
result = nil;
}
}
if (result) {
[thisDict setObject:result
forKey:[NSString stringWithUTF8String:sqlite3_column_name(statement,i)]];
}
}
[thisArray addObject:[NSDictionary dictionaryWithDictionary:thisDict]];
}
}
}
return thisArray;
}
-(void)deleteFromDB:(NSString *)strQuery{
char *error;
if (sqlite3_exec(personDB, [strQuery UTF8String], NULL, NULL, &error)==SQLITE_OK) {
NSLog(@"Person deleted");
}
}
@end
// paste this code in your CustomDB.h file. ("CustomDB.h" <- this is my file name)
#import <Foundation/Foundation.h>
#import <sqlite3.h>
@interface CustomDB : NSObject
{
sqlite3 *personDB;
NSString *dbPathString;
}
-(void)createWith:(NSString *)strFileName;
-(void)insertInToDB:(NSString*)strQuery;
-(NSArray *)selectFromDB:(NSString *)strQuery;
-(void)deleteFromDB:(NSString*)strQuery;
@end
不要忘记在您的桥接标题中添加此行 - ＆gt; #import＆＃34; CustomDB.h＆＃34;并在您的项目中添加sqlite框架......：）
在sqlite数据库中享受这些创建，插入，删除和选择查询：）
答案 4 :(得分：-1)
NSString * docsDict; NSArray * dirPath;
//Get the Dictionary
dirPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);
docsDict = dirPath[0];
NSLog(@"Path : %@",docsDict);
//Build the path to keep the database
_database = [[NSString alloc] initWithString:[docsDict stringByAppendingPathComponent:@"myUser.sql"]];
NSFileManager *fileMngr= [NSFileManager defaultManager];
if([fileMngr fileExistsAtPath:_database] == NO)
{
const char *dbpath = [_database UTF8String];
if(sqlite3_open(dbpath, &_DB) == SQLITE_OK)
{
char *errorMassage;
const char *sql_statement = "CREATE TABLE IF NOT EXISTS users (ID INTEGER PRIMARY KEY AUTOINCREMENT, FIRSTNAME TEXT, LASTNAME TEXT , MOBILENO TEXT)";
if (sqlite3_exec(_DB,sql_statement,NULL,NULL,&errorMassage)!= SQLITE_OK)
{
[self showUIAlertWithMessage:@"Failed to create the table" andTitle:@"error"];
}
sqlite3_close(_DB);
}
else
{
[self showUIAlertWithMessage:@"Failed to open/create the table" andTitle:@"Error"];
}
}