void IDBTraits.RemoveColumn(Func <DbCommand> commandCreator, ColumnReference column)
{
using (DbCommand command = commandCreator()) {
command.CommandText = _SQLQueryManager.RemoveColumn(column);
ExecuteNonQuery(command);
}
}
/// <summary>
/// SQL-92, page 289
/// </summary>
private string _DropColumnDefinition(ColumnReference column)
{
return(string.Format(
"drop column {0} {1}",
nameEscaper(column.columnName), //column name
"" //drop behavior
));
}
ColumnOptions IDBTraits.GetColumnOptions(Func <DbCommand> commandCreator, ColumnReference column)
{
using (DbCommand command = commandCreator())
{
command.CommandText = "select * from user_tab_columns where table_name = :ptable and column_name = :pcolumn";
AddParam(command, "ptable", DbType.String, column.tableName);
AddParam(command, "pcolumn", DbType.String, column.columnName);
using (DbDataReader reader = command.ExecuteReader())
{
if (!reader.Read())
{
throw new ApplicationException("Column not found");
}
string dataType = (string)reader.GetValue("DATA_TYPE");
decimal?dataLength = CastScalarResult <decimal>(reader.GetValue("DATA_LENGTH"));
decimal?dataPrecision = CastScalarResult <decimal>(reader.GetValue("DATA_PRECISION"));
decimal?dataScale = CastScalarResult <decimal>(reader.GetValue("DATA_SCALE"));
string sizeSpecifier = null;
if (dataPrecision.HasValue)
{
if (dataScale.HasValue)
{
sizeSpecifier = string.Format("{0}, {1}", dataPrecision, dataScale);
}
else
{
sizeSpecifier = dataPrecision.ToString();
}
}
else if (dataLength.HasValue)
{
sizeSpecifier = dataLength.ToString();
}
else
{
throw new ApplicationException("Field without a length");
}
string defaultValue = CastResult <string>(reader.GetValue(reader.GetOrdinal("DATA_DEFAULT")));
return(new ColumnOptions(
string.Format("{0}({1})", dataType, sizeSpecifier),
defaultValue != null ? defaultValue.Trim() : null,
!ParseBoolString((string)reader.GetValue(reader.GetOrdinal("NULLABLE")))
));
}
}
}
ColumnOptions IDBTraits.GetColumnOptions(Func <DbCommand> commandCreator, ColumnReference column)
{
using (DbCommand command = commandCreator()) {
command.CommandText = "SELECT a.attnum, a.attname AS field, t.typname AS type, a.attlen AS length, a.atttypmod AS lengthvar, a.attnotnull AS notnull, d.adsrc AS defaultvalue FROM pg_attribute a JOIN pg_class c ON a.attrelid = c.oid JOIN pg_type t ON a.atttypid = t.oid LEFT JOIN pg_attrdef d ON c.oid = d.adrelid AND a.attnum = d.adnum WHERE a.attnum > 0 AND c.relname = :ptable and a.attname = :pcolumn";
AddParam(command, "ptable", DbType.String, column.tableName);
AddParam(command, "pcolumn", DbType.String, column.columnName);
using (DbDataReader reader = ExecuteReader(command)) {
if (!reader.Read())
{
throw new ApplicationException("Column not found");
}
return(new ColumnOptions(
ParseTypeString(reader.GetString(reader.GetOrdinal("type"))),
reader.GetString(reader.GetOrdinal("defaultvalue")),
reader.GetBoolean(reader.GetOrdinal("notnull"))
));
}
}
}
public string RemoveColumn(ColumnReference column)
{
return(_AlterTableStatement(column.tableName, _DropColumnDefinition(column)));
}
public ColumnDescription(ColumnReference column, ColumnOptions options)
{
this.column = column;
this.options = options;
}
public void RemoveColumn(ColumnReference column)
{
this.traits.RemoveColumn(this.CreateTextCommand, column);
}
public ColumnOptions GetColumnOptions(ColumnReference column)
{
return(this.traits.GetColumnOptions(this.CreateTextCommand, column));
}
