/// <summary>
/// Creates a schema from another schema
/// </summary>
/// <param name="S">The starting point schema</param>
/// <param name="K">A key representing the columns to keep</param>
/// <returns>A schema</returns>
public static Schema Split(Schema S, Key K)
{
Schema s = new Schema();
for (int i = 0; i < K.Count; i++)
{
s.Add(S.ColumnName(K[i]), S.ColumnAffinity(K[i]), S.ColumnNull(K[i]), S.ColumnSize(K[i]));
}
return s;
}
// Statics //
/// <summary>
/// Combines two schemas; throws an exception if two columns have the same name.
/// </summary>
/// <param name="S1">The left schema</param>
/// <param name="S2">The right schema</param>
/// <returns>A combined schema</returns>
public static Schema Join(Schema S1, Schema S2)
{
Schema s = new Schema();
for (int i = 0; i < S1.Count; i++)
{
s.Add(S1.ColumnName(i), S1.ColumnAffinity(i), S1.ColumnNull(i), S1.ColumnSize(i));
}
for (int i = 0; i < S2.Count; i++)
{
s.Add(S2.ColumnName(i), S2.ColumnAffinity(i), S2.ColumnNull(i), S2.ColumnSize(i));
}
return s;
}
// Create //
public static CreateTablePlan RenderCreatePlan(Workspace Home, HScriptParser.Crudam_create_tableContext context)
{
// Build visitor //
ExpressionVisitor exp_vis = new ExpressionVisitor(null, Home);
// Build the schema //
Schema columns = new Schema();
foreach (HScriptParser.Create_table_unitContext ctx in context.create_table_unit())
{
columns.Add(
ctx.IDENTIFIER().GetText(),
VisitorHelper.GetAffinity(ctx.type()),
(ctx.expression() == null) ? true : exp_vis.ToNode(ctx.expression()).Evaluate().valueBOOL,
VisitorHelper.GetSize(ctx.type(), true));
}
string name = context.full_table_name().table_name().GetText();
string db = context.full_table_name().database_name().GetText();
string db_path = Home.Connections[db];
long chunk_size =
(context.create_table_size() == null)
? RecordSet.EstimateMaxRecords(columns)
: exp_vis.ToNode(context.create_table_size().expression()).Evaluate().valueINT;
return new CreateTablePlan(db_path, name, columns, (int)chunk_size);
}
public static CreateChunkPlan RenderCreateChunk(Workspace Home, HScriptParser.Crudam_create_tableContext context)
{
ExpressionVisitor exp_vis = new ExpressionVisitor(null, Home);
// Build the schema //
Schema columns = new Schema();
foreach (HScriptParser.Create_table_unitContext ctx in context.create_table_unit())
{
columns.Add(
ctx.IDENTIFIER().GetText(),
VisitorHelper.GetAffinity(ctx.type()),
(ctx.expression() == null) ? true : exp_vis.ToNode(ctx.expression()).Evaluate().valueBOOL,
VisitorHelper.GetSize(ctx.type(), true));
}
string name = context.full_table_name().table_name().IDENTIFIER().GetText();
return new CreateChunkPlan(name, columns, Home);
}
public static Schema Build(Schema S1, string Alias1, Schema S2, string Alias2, string Delim)
{
Schema s = new Schema();
for (int i = 0; i < S1.Count; i++)
s.Add(Alias1 + Delim + S1.ColumnName(i), S1.ColumnAffinity(i), S1.ColumnNull(i), S1.ColumnSize(i));
for (int i = 0; i < S2.Count; i++)
s.Add(Alias2 + Delim + S2.ColumnName(i), S2.ColumnAffinity(i), S2.ColumnNull(i), S2.ColumnSize(i));
return s;
}
