private static void ReadIndexBasedConstraintData(DbDataReader reader, ref IndexBasedConstraintReaderState state,
bool readingCompleted)
{
if (readingCompleted)
{
if (state.Columns.Count > 0)
{
CreateIndexBasedConstraint(ref state);
}
}
else
{
var columnIndex = ReadInt(reader, 5);
if (columnIndex <= state.LastColumnIndex)
{
CreateIndexBasedConstraint(ref state);
state.Columns.Clear();
}
if (state.Columns.Count == 0)
{
var schema = state.Catalog.Schemas[reader.GetString(0)];
state.Table = schema.Tables[reader.GetString(1)];
state.ConstraintName = reader.GetString(2);
state.ConstraintType = reader.GetString(3);
}
state.Columns.Add(state.Table.TableColumns[reader.GetString(4)]);
state.LastColumnIndex = columnIndex;
}
}
private void ExtractUniqueAndPrimaryKeyConstraints(ExtractionContext context)
{
var query = context.PerformReplacements(GetExtractUniqueAndPrimaryKeyConstraintsQuery());
using var reader = ExecuteReader(query);
var state = new IndexBasedConstraintReaderState(context.Catalog);
bool readingCompleted;
do
{
readingCompleted = !reader.Read();
ReadIndexBasedConstraintData(reader, ref state, readingCompleted);
} while (!readingCompleted);
}
private static void CreateIndexBasedConstraint(ref IndexBasedConstraintReaderState state)
{
switch (state.ConstraintType)
{
case "PRIMARY KEY":
_ = state.Table.CreatePrimaryKey(state.ConstraintName, state.Columns.ToArray());
return;
case "UNIQUE":
_ = state.Table.CreateUniqueConstraint(state.ConstraintName, state.Columns.ToArray());
return;
default:
throw new ArgumentOutOfRangeException(nameof(IndexBasedConstraintReaderState.ConstraintType));
}
}
private async Task ExtractUniqueAndPrimaryKeyConstraintsAsync(ExtractionContext context, CancellationToken token)
{
var query = context.PerformReplacements(GetExtractUniqueAndPrimaryKeyConstraintsQuery());
var reader = await ExecuteReaderAsync(query, token).ConfigureAwait(false);
await using (reader.ConfigureAwait(false)) {
var state = new IndexBasedConstraintReaderState(context.Catalog);
bool readingCompleted;
do
{
readingCompleted = !await reader.ReadAsync(token).ConfigureAwait(false);
ReadIndexBasedConstraintData(reader, ref state, readingCompleted);
} while (!readingCompleted);
}
}
//---- ReadIndexBasedConstraintData
// 0 constraint_schema,
// 1 table_name,
// 2 constraint_name,
// 3 constraint_type,
// 4 column_name,
// 5 ordinal_position
private static void ReadIndexBasedConstraintData(DbDataReader reader, ref IndexBasedConstraintReaderState state,
bool readingCompleted)
{
if (readingCompleted)
{
if (state.Columns.Count > 0)
{
CreateIndexBasedConstraint(ref state);
}
}
else
{
var columnIndex = ReadInt(reader, 5);
if (columnIndex <= state.LastColumnIndex)
{
CreateIndexBasedConstraint(ref state);
state.Columns.Clear();
}
if (state.Columns.Count == 0)
{
var schemaName = reader.GetString(0);
var tableName = reader.GetString(1);
var schema = state.Catalog.Schemas[schemaName];
if (schema == null)
{
throw new InvalidOperationException($"Schema '{schemaName}' is not found");
}
state.Table = schema.Tables[tableName];
if (state.Table == null)
{
throw new InvalidOperationException($"Table '{tableName}' is not found in schema '{schemaName}'");
}
state.ConstraintName = reader.GetString(2);
state.ConstraintType = reader.GetString(3);
}
state.Columns.Add(state.Table.TableColumns[reader.GetString(4)]);
state.LastColumnIndex = columnIndex;
}
}
