private DbCommand CreateRemoveCommand(string removeFrom, Expression <Func <ShadowRow, bool> > predicate = null)
{
var sb = new StringBuilder()
.Append("DELETE FROM ")
.Append(removeFrom);
var store = new QueryParametersStore();
if (predicate != null)
{
var w = new WhereQueryTranslator(store, new[] { predicate });
var whereSql = w.TranslateToSql(Expression.Empty());
if (!string.IsNullOrWhiteSpace(whereSql))
{
sb.Append(" WHERE ");
sb.Append(whereSql);
}
}
var cmd = Connection.Value.CreateCommand();
cmd.CommandText = sb.ToString();
foreach (var param in store.GetParams())
{
var p = cmd.CreateParameter();
p.ParameterName = param.Key;
p.Value = param.Value;
cmd.Parameters.Add(p);
}
return(cmd);
}
private DbCommand CreateUpdateCommand(string updateTarget,
Dictionary <string, object> updateFields,
Expression <Func <ShadowRow, bool> > predicate = null)
{
var sb = new StringBuilder()
.Append("UPDATE ")
.Append(updateTarget);
var store = new QueryParametersStore();
var fieldPNameMap = new Dictionary <string, string>();
foreach (var updateField in updateFields)
{
fieldPNameMap[updateField.Key] = store.Append(updateField.Value);
}
{
var setQueryBuilder = new StringBuilder();
var loopCounter = 0;
foreach (var field in fieldPNameMap.Keys)
{
setQueryBuilder.Append($"{field}={fieldPNameMap[field]}");
var itIsLast = loopCounter == fieldPNameMap.Count - 1;
if (!itIsLast)
{
setQueryBuilder.Append(", ");
}
loopCounter++;
}
sb.Append(" SET ");
sb.Append(setQueryBuilder);
}
if (predicate != null)
{
var w = new WhereQueryTranslator(store, new[] { predicate });
var whereSql = w.TranslateToSql(Expression.Empty());
if (!string.IsNullOrWhiteSpace(whereSql))
{
sb.Append(" WHERE ");
sb.Append(whereSql);
}
}
var cmd = Connection.Value.CreateCommand();
cmd.CommandText = sb.ToString();
foreach (var param in store.GetParams())
{
var p = cmd.CreateParameter();
p.ParameterName = param.Key;
p.Value = param.Value;
cmd.Parameters.Add(p);
}
return(cmd);
}