using Sqlite; namespace Qlite { public class DeleteBuilder : StatementBuilder { // DELETE FROM [...] private Table table; private string table_name; // WHERE [...] private string selection; private StatementBuilder.Field[] selection_args; protected DeleteBuilder(Database db) { base(db); } public DeleteBuilder from(Table table) throws DatabaseError { if (this.table != null) throw new DatabaseError.ILLEGAL_QUERY("cannot use from() multiple times."); this.table = table; this.table_name = table.name; return this; } public DeleteBuilder from_name(string table) { this.table_name = table; return this; } public DeleteBuilder where(string selection, string[]? selection_args = null) throws DatabaseError { if (this.selection != null) throw new DatabaseError.ILLEGAL_QUERY("selection was already done, but where() was called."); this.selection = selection; if (selection_args != null) { this.selection_args = new StatementBuilder.Field[selection_args.length]; for (int i = 0; i < selection_args.length; i++) { this.selection_args[i] = new StatementBuilder.StringField(selection_args[i]); } } return this; } public DeleteBuilder with(Column column, string comp, T value) { if (selection == null) { selection = @"$(column.name) $comp ?"; selection_args = { new StatementBuilder.Field(column, value) }; } else { selection = @"($selection) AND $(column.name) $comp ?"; StatementBuilder.Field[] selection_args_new = new StatementBuilder.Field[selection_args.length+1]; for (int i = 0; i < selection_args.length; i++) { selection_args_new[i] = selection_args[i]; } selection_args_new[selection_args.length] = new Field(column, value); selection_args = selection_args_new; } return this; } public override Statement prepare() throws DatabaseError { Statement stmt = db.prepare(@"DELETE FROM $table_name $(selection != null ? @"WHERE $selection": "")"); for (int i = 0; i < selection_args.length; i++) { selection_args[i].bind(stmt, i+1); } return stmt; } public void perform() throws DatabaseError { if (prepare().step() != DONE) { throw new DatabaseError.EXEC_ERROR(@"SQLite error: $(db.errcode()) - $(db.errmsg())"); } } } }