Example: Prepared statements:
public static int main (string[] args) {
Sqlite.Database db;
string errmsg;
// Open a database:
int ec = Sqlite.Database.open ("test.db", out db);
if (ec != Sqlite.OK) {
stderr.printf ("Can't open database: %d: %s\n", db.errcode (), db.errmsg ());
return -1;
}
// Insert test data:
string query = """
CREATE TABLE User (
id INT PRIMARY KEY NOT NULL,
name TEXT NOT NULL
);
INSERT INTO User (id, name) VALUES (1, 'Hesse');
INSERT INTO User (id, name) VALUES (2, 'Frisch');
""";
ec = db.exec (query, null, out errmsg);
if (ec != Sqlite.OK) {
stderr.printf ("Error: %s\n", errmsg);
return -1;
}
//
// Create a prepared statement:
// (db.prepare shouldn't be used anymore)
//
Sqlite.Statement stmt;
const string prepared_query_str = "SELECT * FROM User WHERE id = $UID;";
ec = db.prepare_v2 (prepared_query_str, prepared_query_str.length, out stmt);
if (ec != Sqlite.OK) {
stderr.printf ("Error: %d: %s\n", db.errcode (), db.errmsg ());
return -1;
}
//
// Use the prepared statement:
//
int param_position = stmt.bind_parameter_index ("$UID");
assert (param_position > 0);
stmt.bind_int (param_position, 1);
int cols = stmt.column_count ();
while (stmt.step () == Sqlite.ROW) {
for (int i = 0; i < cols; i++) {
string col_name = stmt.column_name (i) ?? "<none>";
string val = stmt.column_text (i) ?? "<none>";
int type_id = stmt.column_type (i);
print ("column: %s\n", col_name);
print ("value: %s\n", val);
print ("type: %d\n", type_id);
}
}
// Output:
// ``column: id``
// ``value: 1``
// ``type: 1``
// ``column: name``
// ``value: Hesse``
// ``type: 3``
// Reset the statement to rebind parameters:
stmt.reset ();
// ...
return 0;
}valac --pkg sqlite3 prepared-statements.vala