2、CONVERT() CONVERT (<data_ type>[ length ], <expression> [, style]) 1)data_type为SQL Server系统定义的数据类型,用户自定义的数据类型不能在此使用。 2)length用于指定数据的长度,缺省值为30。 3)把CHAR或VARCHAR类型转换为诸如INT或SAMLLINT这样的INTEGER类型、结果必须是带正号或负号的数值。 4)TEXT...
{publicstaticstringdataBaseFileName = AppDomain.CurrentDomain.BaseDirectory +"goods.db";publicstaticstringconnectionString =@"Data Source="+ dataBaseFileName +"; Pooling=true;FailIfMissing=false;";publicDBHelperSQLite() { }publicstaticvoidExistsDataBase() {if(!File.Exists(dataBaseFileName)) { SQLi...
--插入--注意:Integer允许自动增长(不要被Identity 忽悠)insertintoUserInfo(UserId,UserNames,UserPasss,RegDate)values(1001,'admin','admin','2021-01-21')insertintoUserInfo(UserId,UserNames,UserPasss,RegDate)values(1002,'sanha','sanha', datetime('now','localtime'))--查询select*fromUserInfo--Li...
static bool CreateTable(string db) { try { using (var con = new SQLiteConnection(db)) { con.Open(); using (var cmd = new SQLiteCommand(con)) { cmd.CommandText = "DROP TABLE IF EXISTS PrintDataInfo"; cmd.ExecuteNonQuery(); cmd.CommandText = @"CREATE TABLE PrintDataInfo(id INTEGER PR...
if (InsertData(myDb, txtFullSN.Text, Convert.ToInt32(txtMeterID.Text), txtOrderNr.Text)) { txtMessage.Text = "插入数据成功"; } else { txtMessage.Text = "插入数据失败"; } } 4. 查询数据 static List<string> ReadData(string db) ...
auth_user_addusernamestring, passwordstring, adminintThis function will add an user to the database. if the database is not protected by user authentication it will enable it. Argumentadminis an integer identifying if the added user should be an administrator. Only Administrators can add administ...
//Insertable:表示一个可插入的对象,有方法ContentValues convert(),将Entitiy转换为ContentValues public class FooEntity implements Queryable, Insertable { /** * 数据库自增id */ private int id; /** * entitiy id */ private String fooId;
4 = '4' is FALSE, because neither has a type affinity and sqlite compares an integer with a string amount = '4' is TRUE when a 4 is stored in the row, because since amount has a type affinity of REAL, sqlite expects all the values contained should be real and converts ...
Add SQLite keywords convert function to avoid keywords conflict. Fix bug of DateSupport.count error. Fix bug of losing blob data when upgrading database. Fix other known bugs. Improve an outstanding speed up of querying and saving. Support to store database file in external storage. ...
The table that the new column will be added to. The table name will be properly quoted by the method. $column string The name of the new column. The name will be properly quoted by the method. $type string The column type. The getColumnType() method will be invoked to convert abstrac...