public static bool CheckIfTableExists(this CrateConnection conn, string name)
{
var ret = new List <Table>();
var sql = "SELECT * FROM information_schema.tables WHERE table_name= '" + name + "'";
using (var cmd = new CrateCommand(sql, conn))
{
var reader = (CrateDataReader)cmd.ExecuteReader();
ret = reader.ToList <Table>();
}
return(ret.Count > 0);
}
public static List <T> Where <T>(this CrateConnection cnn, Expression <Func <T, bool> > exp) where T : class, new()
{
List <T> ret;
var table = AttributeHelpers.GetTableData(typeof(T));
var swhere = "SELECT * FROM " + table.Name + " WHERE " + (new WhereTranslater()).Translate(exp);
using (var cmd = new CrateCommand(swhere, cnn))
{
var reader = (CrateDataReader)cmd.ExecuteReader();
ret = reader.ToList <T>();
}
return(ret);
}
public static List <TOut> Execute <T, TOut>(this CrateConnection cnn, Expression <Func <List <T>, IEnumerable <TOut> > > exp)
where T : class, new()
where TOut : class, new()
{
List <TOut> ret;
var table = AttributeHelpers.GetTableData(typeof(T));
var sql = (new Translater(table.Name)).Translate(exp);
using (var cmd = new CrateCommand(sql, cnn))
{
var reader = (CrateDataReader)cmd.ExecuteReader();
ret = reader.ToList <TOut>();
}
return(ret);
}
public static long Count <T>(this CrateConnection cnn, Expression <Func <T, bool> > exp = null) where T : class, new()
{
long ret = 0;
var table = AttributeHelpers.GetTableData(typeof(T));
var swhere = "SELECT count(*) FROM " + table.Name;
if (exp != null)
{
swhere += " WHERE " + (new WhereTranslater()).Translate(exp);
}
using (var cmd = new CrateCommand(swhere, cnn))
{
var reader = (CrateDataReader)cmd.ExecuteReader();
if (reader.Read())
{
ret = reader.GetLong(0);
}
}
return(ret);
}