anotherim-desktop/qlite/src/update_builder.vala
2017-03-10 17:33:27 +01:00

134 lines
4.4 KiB
Vala

using Sqlite;
namespace Qlite {
public class UpdateBuilder : StatementBuilder {
// UPDATE [OR ...]
private string or_val;
// [...]
private Table table;
private string table_name;
// SET [...]
private StatementBuilder.Field[] fields;
// WHERE [...]
private string selection;
private StatementBuilder.Field[] selection_args;
protected UpdateBuilder(Database db, Table table) {
base(db);
this.table = table;
this.table_name = table.name;
}
internal UpdateBuilder.for_name(Database db, string table) {
base(db);
this.table_name = table;
}
public UpdateBuilder or(string or) {
this.or_val = or;
return this;
}
public UpdateBuilder set<T>(Column<T> column, T value) {
if (fields == null) {
fields = { new StatementBuilder.Field<T>(column, value) };
} else {
StatementBuilder.Field[] fields_new = new StatementBuilder.Field[fields.length+1];
for (int i = 0; i < fields.length; i++) {
fields_new[i] = fields[i];
}
fields_new[fields.length] = new Field<T>(column, value);
fields = fields_new;
}
return this;
}
public UpdateBuilder set_null<T>(Column<T> column) throws DatabaseError {
if (column.not_null) throw new DatabaseError.ILLEGAL_QUERY(@"Can't set non-null column $(column.name) to null");
if (fields == null) {
fields = { new NullField<T>(column) };
} else {
StatementBuilder.Field[] fields_new = new StatementBuilder.Field[fields.length+1];
for (int i = 0; i < fields.length; i++) {
fields_new[i] = fields[i];
}
fields_new[fields.length] = new NullField<T>(column);
fields = fields_new;
}
return this;
}
public UpdateBuilder where(string selection, string[]? selection_args = null) throws DatabaseError {
if (this.selection != null) throw new DatabaseError.ILLEGAL_QUERY("selection was already done, but where() was called.");
this.selection = selection;
if (selection_args != null) {
this.selection_args = new StatementBuilder.Field[selection_args.length];
for (int i = 0; i < selection_args.length; i++) {
this.selection_args[i] = new StatementBuilder.StringField(selection_args[i]);
}
}
return this;
}
public UpdateBuilder with<T>(Column<T> column, string comp, T value) {
if (selection == null) {
selection = @"$(column.name) $comp ?";
selection_args = { new StatementBuilder.Field<T>(column, value) };
} else {
selection = @"($selection) AND $(column.name) $comp ?";
StatementBuilder.Field[] selection_args_new = new StatementBuilder.Field[selection_args.length+1];
for (int i = 0; i < selection_args.length; i++) {
selection_args_new[i] = selection_args[i];
}
selection_args_new[selection_args.length] = new Field<T>(column, value);
selection_args = selection_args_new;
}
return this;
}
public UpdateBuilder with_null<T>(Column<T> column) {
selection = @"($selection) AND $(column.name) ISNULL";
return this;
}
public UpdateBuilder without_null<T>(Column<T> column) {
selection = @"($selection) AND $(column.name) NOT NULL";
return this;
}
public override Statement prepare() throws DatabaseError {
string sql = "UPDATE";
if (or_val != null) sql += @" OR $or_val";
sql += @" $table_name SET ";
for (int i = 0; i < fields.length; i++) {
if (i != 0) {
sql += ", ";
}
sql += @"$(fields[i].column.name) = ?";
}
sql += @" WHERE $selection";
Statement stmt = db.prepare(sql);
for (int i = 0; i < fields.length; i++) {
fields[i].bind(stmt, i+1);
}
for (int i = 0; i < selection_args.length; i++) {
selection_args[i].bind(stmt, i + fields.length + 1);
}
return stmt;
}
public void perform() throws DatabaseError {
if (fields == null || fields.length == 0) return;
if (prepare().step() != DONE) {
throw new DatabaseError.EXEC_ERROR(@"SQLite error: $(db.errcode()) - $(db.errmsg())");
}
}
}
}