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有人可能会这么热心填写下面几段缺少的代码。我正在努力使用sqlite3_step执行一个sqlite语句,迭代每行结果并将数据转换为可用格式。如何通过sqlite_step结果进行迭代
下面是创建数据库(Database是仅有的两个colums)
// Check if database is setup, if not create it
NSString *documents_directory;
NSArray *directory_path;
// Get the documents directory
directory_path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
documents_directory = [directory_path objectAtIndex:0];
// Build the path to the database file
databasePath = [[NSString alloc] initWithString: [documents_directory stringByAppendingPathComponent: @"weights.db"]];
NSFileManager *file_manager = [NSFileManager defaultManager];
// Create database if it doesn't already exist
if([file_manager fileExistsAtPath: databasePath ] == NO){
const char *database_path = [databasePath UTF8String];
if(sqlite3_open(database_path, &contactDB) == SQLITE_OK){
char *error_message;
const char *sql_statement = "CREATE TABLE IF NOT EXISTS RECORDED_WEIGHTS (ID INTEGER PRIMARY KEY AUTOINCREMENT, WEIGHT TEXT, TIME TEXT)";
if(sqlite3_exec(contactDB, sql_statement, NULL, NULL, &error_message) != SQLITE_OK){
status.text = @"Failed to create table";
}
sqlite3_close(contactDB);
}else{
status.text = @"Failed to open/create database";
}
}
这里是我试图完成代码的代码;
// Get info from database and load it.
const char *database_path = [databasePath UTF8String];
sqlite3_stmt *statement;
if(sqlite3_open(database_path, &contactDB) == SQLITE_OK){
NSString *SQLquery = [NSString stringWithFormat:@"SELECT * FROM RECORDED_WEIGHTS ORDER BY TIME DESC"];
const char *query_statement = [SQLquery UTF8String];
if(sqlite3_prepare_v2(contactDB, query_statement, -1, &statement, NULL) == SQLITE_OK){
// Please help me execute statement and get results into useable format here.
}
sqlite3_finalize(statement);
}
sqlite3_close(contactDB);
在此先感谢。