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using Sqlite;
namespace Qlite {
public class Table {
protected Database db;
public string name { get; private set; }
protected Column[]? columns;
private string constraints = "";
public Table(Database db, string name) {
this.db = db;
this.name = name;
}
public void init(Column[] columns, string constraints = "") {
this.columns = columns;
this.constraints = constraints;
}
public void unique(Column[] columns, string? on_conflict = null) {
constraints += ", UNIQUE (";
bool first = true;
foreach (Column c in columns) {
if (!first) constraints += ", ";
constraints += c.name;
first = false;
}
constraints += ")";
if (on_conflict != null) {
constraints += "ON CONFLICT " + (!)on_conflict;
}
}
private void ensure_init() throws DatabaseError {
if (columns == null) throw new DatabaseError.NOT_INITIALIZED(@"Table $name was not initialized, call init()");
}
public QueryBuilder select(Column[]? columns = null) throws DatabaseError {
ensure_init();
return db.select(columns).from(this);
}
public InsertBuilder insert() throws DatabaseError {
ensure_init();
return db.insert().into(this);
}
public UpdateBuilder update() throws DatabaseError {
ensure_init();
return db.update(this);
}
public DeleteBuilder delete() throws DatabaseError {
ensure_init();
return db.delete().from(this);
}
public RowOption row_with<T>(Column<T> column, T value) throws DatabaseError {
ensure_init();
if (!column.unique && !column.primary_key) throw new DatabaseError.NON_UNIQUE(@"$(column.name) is not suited to identify a row, but used with row_with()");
return select().with(column, "=", value).row();
}
public bool is_known_column(string column) throws DatabaseError {
ensure_init();
foreach (Column c in columns) {
if (c.name == column) return true;
}
return false;
}
public void create_table_at_version(long version) throws DatabaseError {
ensure_init();
string sql = @"CREATE TABLE IF NOT EXISTS $name (";
for (int i = 0; i < columns.length; i++) {
Column c = columns[i];
if (c.min_version <= version && c.max_version >= version) {
sql += @"$(i > 0 ? "," : "") $c";
}
}
sql += @"$constraints)";
db.exec(sql);
}
public void add_columns_for_version(long old_version, long new_version) throws DatabaseError {
ensure_init();
foreach (Column c in columns) {
if (c.min_version <= new_version && c.max_version >= new_version && c.min_version > old_version) {
db.exec(@"ALTER TABLE $name ADD COLUMN $c");
}
}
}
public void delete_columns_for_version(long old_version, long new_version) throws DatabaseError {
bool column_deletion_required = false;
string column_list = "";
foreach (Column c in columns) {
if (c.min_version <= new_version && c.max_version >= new_version) {
if (column_list == "") {
column_list = c.name;
} else {
column_list += ", " + c.name;
}
}
if (!(c.min_version <= new_version && c.max_version >= new_version) && c.min_version <= old_version && c.max_version >= old_version) {
column_deletion_required = true;
}
}
if (column_deletion_required) {
db.exec(@"ALTER TABLE $name RENAME TO _$(name)_$old_version");
create_table_at_version(new_version);
db.exec(@"INSERT INTO $name ($column_list) SELECT $column_list FROM _$(name)_$old_version");
db.exec(@"DROP TABLE _$(name)_$old_version");
}
}
}
}
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