anotherim-desktop/qlite/src/delete_builder.vala

75 lines
2.5 KiB
Vala

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;
internal 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<T>(Column<T> column, string comp, T value) {
if (selection == null) {
selection = @"$(column.name) $comp ?";
selection_args = { new StatementBuilder.Field<T>(column, value) };
} else {
selection = @"($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<T>(column, value);
selection_args = selection_args_new;
}
return this;
}
internal 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())");
}
}
}
}