/// <summary>
/// Retrieves foreign key information from the specified set of filters
/// </summary>
/// <param name="strCatalog">An optional catalog to restrict results on</param>
/// <param name="strTable">An optional table to restrict results on</param>
/// <param name="strKeyName">An optional foreign key name to restrict results on</param>
/// <returns>A DataTable with the results of the query</returns>
private DataTable Schema_ForeignKeys(string strCatalog, string strTable, string strKeyName)
{
DataTable tbl = new DataTable("ForeignKeys");
DataRow row;
tbl.Locale = CultureInfo.InvariantCulture;
tbl.Columns.Add("CONSTRAINT_CATALOG", typeof(string));
tbl.Columns.Add("CONSTRAINT_SCHEMA", typeof(string));
tbl.Columns.Add("CONSTRAINT_NAME", typeof(string));
tbl.Columns.Add("TABLE_CATALOG", typeof(string));
tbl.Columns.Add("TABLE_SCHEMA", typeof(string));
tbl.Columns.Add("TABLE_NAME", typeof(string));
tbl.Columns.Add("CONSTRAINT_TYPE", typeof(string));
tbl.Columns.Add("IS_DEFERRABLE", typeof(bool));
tbl.Columns.Add("INITIALLY_DEFERRED", typeof(bool));
tbl.Columns.Add("FKEY_ID", typeof(int));
tbl.Columns.Add("FKEY_FROM_COLUMN", typeof(string));
tbl.Columns.Add("FKEY_FROM_ORDINAL_POSITION", typeof(int));
tbl.Columns.Add("FKEY_TO_CATALOG", typeof(string));
tbl.Columns.Add("FKEY_TO_SCHEMA", typeof(string));
tbl.Columns.Add("FKEY_TO_TABLE", typeof(string));
tbl.Columns.Add("FKEY_TO_COLUMN", typeof(string));
tbl.Columns.Add("FKEY_ON_UPDATE", typeof(string));
tbl.Columns.Add("FKEY_ON_DELETE", typeof(string));
tbl.Columns.Add("FKEY_MATCH", typeof(string));
if (String.IsNullOrEmpty(strCatalog)) strCatalog = "main";
string master = (String.Compare(strCatalog, "temp", StringComparison.OrdinalIgnoreCase) == 0) ? _tempmasterdb : _masterdb;
tbl.BeginLoadData();
using (SQLiteCommand cmdTables = new SQLiteCommand(String.Format(CultureInfo.InvariantCulture, "SELECT * FROM [{0}].[{1}] WHERE [type] LIKE 'table'", strCatalog, master), this))
using (SQLiteDataReader rdTables = cmdTables.ExecuteReader())
{
while (rdTables.Read())
{
if (String.IsNullOrEmpty(strTable) || String.Compare(strTable, rdTables.GetString(2), StringComparison.OrdinalIgnoreCase) == 0)
{
try
{
using (SQLiteCommandBuilder builder = new SQLiteCommandBuilder())
//using (SQLiteCommand cmdTable = new SQLiteCommand(String.Format(CultureInfo.InvariantCulture, "SELECT * FROM [{0}].[{1}]", strCatalog, rdTables.GetString(2)), this))
//using (SQLiteDataReader rdTable = cmdTable.ExecuteReader(CommandBehavior.SchemaOnly))
using (SQLiteCommand cmdKey = new SQLiteCommand(String.Format(CultureInfo.InvariantCulture, "PRAGMA [{0}].foreign_key_list([{1}])", strCatalog, rdTables.GetString(2)), this))
using (SQLiteDataReader rdKey = cmdKey.ExecuteReader())
{
while (rdKey.Read())
{
row = tbl.NewRow();
row["CONSTRAINT_CATALOG"] = strCatalog;
row["CONSTRAINT_NAME"] = String.Format(CultureInfo.InvariantCulture, "FK_{0}_{1}_{2}", rdTables[2], rdKey.GetInt32(0), rdKey.GetInt32(1));
row["TABLE_CATALOG"] = strCatalog;
row["TABLE_NAME"] = builder.UnquoteIdentifier(rdTables.GetString(2));
row["CONSTRAINT_TYPE"] = "FOREIGN KEY";
row["IS_DEFERRABLE"] = false;
row["INITIALLY_DEFERRED"] = false;
row["FKEY_ID"] = rdKey[0];
row["FKEY_FROM_COLUMN"] = builder.UnquoteIdentifier(rdKey[3].ToString());
row["FKEY_TO_CATALOG"] = strCatalog;
row["FKEY_TO_TABLE"] = builder.UnquoteIdentifier(rdKey[2].ToString());
row["FKEY_TO_COLUMN"] = builder.UnquoteIdentifier(rdKey[4].ToString());
row["FKEY_FROM_ORDINAL_POSITION"] = rdKey[1];
row["FKEY_ON_UPDATE"] = (rdKey.FieldCount > 5) ? rdKey[5] : String.Empty;
row["FKEY_ON_DELETE"] = (rdKey.FieldCount > 6) ? rdKey[6] : String.Empty;
row["FKEY_MATCH"] = (rdKey.FieldCount > 7) ? rdKey[7] : String.Empty;
if (String.IsNullOrEmpty(strKeyName) || String.Compare(strKeyName, row["CONSTRAINT_NAME"].ToString(), StringComparison.OrdinalIgnoreCase) == 0)
tbl.Rows.Add(row);
}
}
}
catch (SQLiteException)
{
}
}
}
}
tbl.EndLoadData();
tbl.AcceptChanges();
return tbl;
}
