一、选择列表 选择列表(select_list)指出所查询列,它可以是一组列名列表、星号、表达式、变量(包括局部变量和全局变量)等构成。 1、选择所有列 例如,下面语句显示testtable表中所有列的数据: SELECT *FROM testtable 2、选择部分列并指定它们的显示次序 查询结果集合中数据的排列顺序与选择列表中所指定的列名排列顺序...
execute("select info,flag,result from user where info='XXX'") print(len(list(cursor))) 10.SQLite 数据类型 存储类 描述 NULL 值是一个 NULL 值。 INTEGER 值是一个带符号的整数,根据值的大小存储在 1、2、3、4、6 或 8 字节中。 REAL 值是一个浮点值,存储为 8 字节的 IEEE 浮点数字。 TEXT...
调过来的,作用是解析所有select|insert|update|delete 放入一个list 中 private void buildStatementFromContext(List<XNode> list) { if (configuration.getDatabaseId() != null) { buildStatementFromContext(list, configuration.getDatabaseId()); } buildStatementFromContext(list, null); } 1. 2. 3. 4...
1. where column_name not in ('name1','name2') 2.db.query(TABLE,new String[]{"id",""},String.format(" type NOT IN (%s)",argsArrayToString(arrays)),null,null,null,null); You cannot place just one '?' instead of a list of values. As such, there is little to gain from tryi...
in fieldList) { createTable += field[1]+$" `{field[2]}` "+ (field[3].Equals(1) ? "NOT NULL" : "")+","; if (field[5].Equals("1")) { pk= field[1]; } } if (!string.IsNullOrEmpty(pk)) { createTable += $"
" for key in change['data'].keys()]) cursor.execute(f"UPDATE {change['table_name']} SET {set_clause} WHERE id = ?", list(change['data'].values()) + [change['data']['id']]) elif change['operation'] == 'DELETE': cursor.execute(f"DELETE FROM {change['table_name']} WHERE...
set null:父表delete、update的时候,子表会将关联记录的外键字段所在列设为null,所以注意在设计子表时外键不能设为not null; delete和truncate都是用来删除表中的数据的他们的区别是: DQL:【重点】 查询的完整语法: SELECT selection_list /*要查询的列名称*/ ...
=nulltry{cursor=schoolDbHelper.getDB().rawQuery("select count(*) from $tblName",null)if(cursor.moveToFirst()){count=cursor.getInt(0)}}catch(e:Exception){e.printStackTrace()}finally{cursor?.close()schoolDbHelper.closeDB()}returncount}@SuppressLint("Range")funselect(count:Int):List<Student...
Details for the issue Version: 3.10.0 Beta1 OS: Win10 Home 1703 Application binary does not seem react to commandline options (using command prompt) in "expected" ways. For example, invoking the application with "--help" does not yield t...
implements the IEnumerable<T> interface and can also be queried with LINQ. The actual returned result consists of a list of <T> objects; however, binding a TableQuery object to the UI directly is not the proper way to present data, so a new ObservableCollection<Customer> based on the ...