嘿伙计们，我只是在玩SQLite，所以这对我来说很新。我有一个视图，可以保存和找到人员数据。 save-function和find-function工作得很好。现在，我有一个带有tableView的新视图。我想让联系人表中的所有人都填上清单。
到现在为止，我已经：
-(void)viewWillAppear:(BOOL)animated {
const char *dbpath = [databasePath UTF8String];
sqlite3_stmt *statement;
if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK)
{
NSLog(@"Opened DB");
NSString *querySQL = [NSString stringWithFormat:@"SELECT name FROM contacts"];
const char *query_stmt = [querySQL UTF8String];
NSLog(@"could not prepare statement: %s\n", sqlite3_errmsg(contactDB));
if (sqlite3_prepare_v2(contactDB, query_stmt, -1, &statement, NULL) == SQLITE_OK)
//if (sqlite3_step(query_stmt) == SQLITE_DONE)
{
//NSLog(@"SQLite OK");
NSLog(@"SQLite ok");
//if (sqlite3_step(statement) == SQLITE_ROW)
//{
while(sqlite3_step(statement) == SQLITE_ROW) {
NSLog(@"SQLite ROW");
NSString *person = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 0)];
[personsList addObject:person];
}
//} else {
// NSLog(@"Emtpy list");
//}
sqlite3_finalize(statement);
}
sqlite3_close(contactDB);
}
NSLog(@"Calling reload");
NSLog(@"%@", personsList);
[tabelView reloadData];
}
这都在viewWillAppear中。加载并完成视图后，日志显示：2011-05-06 10:45:26.976 database[1412:207] Opened DB
2011-05-06 10:45:26.978 database[1412:207] could not prepare statement: not an error
2011-05-06 10:45:26.979 database[1412:207] Calling reload
2011-05-06 10:45:26.979 database[1412:207] (
)
所以看起来这个语句不是错误，但sqlite3_prepare_v2毕竟不是SQL_OK。有帮助吗？
编辑：在上一个视图中，创建人的声明是：@"INSERT INTO CONTACTS (name, address, phone) VALUES (\"%@\", \"%@\", \"%@\")", name.text, address.text, phone.text];
寻找某人的声明是：@"SELECT address, phone FROM contacts WHERE name=\"%@\"", name.text];
这两个语句起作用并显示数据。
@joetjah我用你的代码来获取结果，它运行正常
2011-05-06 16:03:00.076 SQLiteDemo[6454:207] Opened DB
2011-05-06 16:03:09.550 SQLiteDemo[6454:207] could not prepare statement: not an error
2011-05-06 16:03:24.685 SQLiteDemo[6454:207] SQLite ok
2011-05-06 16:03:26.229 SQLiteDemo[6454:207] SQLite ROW
2011-05-06 16:03:28.254 SQLiteDemo[6454:207] SQLite ROW
2011-05-06 16:03:34.461 SQLiteDemo[6454:207] Calling reload
2011-05-06 16:03:35.009 SQLiteDemo[6454:207] (
rahul,
sqlite
)
-(void)testFunction{
const char *dbpath = [databasePath UTF8String];
sqlite3_stmt *statement;
sqlite3 *contactDB;
NSMutableArray *personsList = [[NSMutableArray alloc ] initWithCapacity:0];
if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK)
{
NSLog(@"Opened DB");
NSString *querySQL = [NSString stringWithFormat:@"SELECT name FROM contacts"];
const char *query_stmt = [querySQL UTF8String];
NSLog(@"could not prepare statement: %s\n", sqlite3_errmsg(contactDB));
if (sqlite3_prepare_v2(contactDB, query_stmt, -1, &statement, NULL) == SQLITE_OK)
//if (sqlite3_step(query_stmt) == SQLITE_DONE)
{
//NSLog(@"SQLite OK");
NSLog(@"SQLite ok");
//if (sqlite3_step(statement) == SQLITE_ROW)
//{
while(sqlite3_step(statement) == SQLITE_ROW) {
NSLog(@"SQLite ROW");
NSString *person = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 0)];
[personsList addObject:person];
}
//} else {
// NSLog(@"Emtpy list");
//}
sqlite3_finalize(statement);
}
sqlite3_close(contactDB);
}
NSLog(@"Calling reload");
NSLog(@"%@", personsList);
//[tabelView reloadData];
}
您可以比较代码，可能的失败点可能是1]数据未正确保存，因此无法获取任何内容。 2] databasePath被设置为空白（我怀疑你得到Open Db日志）
表联系人是使用“CREATE TABLE contacts（name text，age integer）”创建的，请尝试一次，让我知道它是否有效。
试试这个，
-(void)viewWillAppear:(BOOL)animated {
// Override point for customization after app launch.
// Setup some globals
// Get the path to the documents directory and append the databaseName
NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDir = [documentPaths objectAtIndex:0];
databasePath = [documentsDir stringByAppendingPathComponent:@"contacts.db"];
const char *dbpath = [databasePath UTF8String];
sqlite3_stmt *statement;
if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK)
{
NSLog(@"Opened DB");
NSString *querySQL = [NSString stringWithFormat:@"SELECT name FROM CONTACTS"];
const char *query_stmt = [querySQL UTF8String];
NSLog(@"could not prepare statement: %s\n", sqlite3_errmsg(contactDB));
if (sqlite3_prepare_v2(contactDB, query_stmt, -1, &statement, NULL) == SQLITE_OK)
{
NSLog(@"SQLite ok");
while(sqlite3_step(statement) == SQLITE_ROW) {
NSLog(@"SQLite ROW");
NSString *person = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 0)];
[personsList addObject:person];
}
sqlite3_finalize(statement);
}
else
{
//NSLog(@"could not prepare statement: %s\n", sqlite3_errmsg(statement));
}
sqlite3_close(contactDB);
}
NSLog(@"Calling reload");
NSLog(@"%@", personsList);
[tabelView reloadData];
}
我使用const char *dbpath = [databasePath UTF8String];，但我忘记在它上面添加以下代码：
// Get the documents directory
NSString *docsDir;
NSArray *dirPaths;
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
docsDir = [dirPaths objectAtIndex:0];
databasePath = [[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent: @"contacts.db"]];
const char *dbpath = [databasePath UTF8String];
这对我有用：
在didload函数中创建表，然后将其添加（假设您已声明其他表视图函数）：
public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell{
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! TableViewCell
var selectStatement: OpaquePointer? = nil
let selectSql = "select * from Inventory where ID = \((indexPath.row + 1))"
if sqlite3_prepare_v2(Database.database.sqliteDB, selectSql, -1, &selectStatement, nil) == SQLITE_OK{
if sqlite3_step(selectStatement) == SQLITE_ROW {
let nameItem = sqlite3_column_text(selectStatement, 1)
let price = sqlite3_column_double(selectStatement, 2)
let quantity = sqlite3_column_int(selectStatement, 3)
let nameString = String(cString: nameItem!)
let priceString = String(format: "%.1f",price)
let quantityString = String(quantity)
cell.itemName.text = nameString
cell.itemPrice.text = priceString
cell.itemQuantity.text = quantityString
}
}
return cell
}