db: catch SQL errors unless we're expecting them.

I couldn't figure out why my new SQL query was returning 0 rows,
and it was because we were ignoring errors.

Signed-off-by: Rusty Russell <[email protected]>

db/exec.c

@@ -25,7 +25,7 @@ int db_get_version(struct db *db)
 	 * table that doesn't exist yet, so we need to terminate and restart
 	 * the DB transaction.
 	 */
-	if (!db_query_prepared(stmt)) {
+	if (!db_query_prepared_canfail(stmt)) {
 		db_commit_transaction(stmt->db);
 		db_begin_transaction(stmt->db);
 		tal_free(stmt);
@@ -45,7 +45,7 @@ u32 db_data_version_get(struct db *db)
 	u32 version;
 	stmt = db_prepare_v2(db, SQL("SELECT intval FROM vars WHERE name = 'data_version'"));
 	/* postgres will act upset if the table doesn't exist yet. */
-	if (!db_query_prepared(stmt)) {
+	if (!db_query_prepared_canfail(stmt)) {
 		tal_free(stmt);
 		return 0;
 	}
@@ -85,7 +85,7 @@ s64 db_get_intvar(struct db *db, char *varname, s64 defval)
 	struct db_stmt *stmt = db_prepare_v2(
 	    db, SQL("SELECT intval FROM vars WHERE name= ? LIMIT 1"));
 	db_bind_text(stmt, 0, varname);
-	if (db_query_prepared(stmt) && db_step(stmt))
+	if (db_query_prepared_canfail(stmt) && db_step(stmt))
 		res = db_col_int(stmt, "intval");
 
 	tal_free(stmt);

db/utils.c

@@ -135,7 +135,7 @@ struct db_stmt *db_prepare_untranslated(struct db *db, const char *query)
 	return stmt;
 }
 
-bool db_query_prepared(struct db_stmt *stmt)
+bool db_query_prepared_canfail(struct db_stmt *stmt)
 {
 	/* Make sure we don't accidentally execute a modifying query using a
 	 * read-only path. */
@@ -147,6 +147,13 @@ bool db_query_prepared(struct db_stmt *stmt)
 	return ret;
 }
 
+void db_query_prepared(struct db_stmt *stmt)
+{
+	if (!db_query_prepared_canfail(stmt))
+		db_fatal("query failed: %s: %s",
+			 stmt->location, stmt->query->query);
+}
+
 bool db_step(struct db_stmt *stmt)
 {
 	bool ret;

db/utils.h

@@ -49,7 +49,12 @@ bool db_exec_prepared_v2(struct db_stmt *stmt TAKES);
  *
  * @stmt: The prepared statement to execute
  */
-bool db_query_prepared(struct db_stmt *stmt);
+void db_query_prepared(struct db_stmt *stmt);
+
+/**
+ * Variation which allows failure.
+ */
+bool db_query_prepared_canfail(struct db_stmt *stmt);
 
 size_t db_count_changes(struct db_stmt *stmt);
 void db_report_changes(struct db *db, const char *final, size_t min);

wallet/test/run-db.c

@@ -224,7 +224,7 @@ static bool test_manip_columns(void)
 	CHECK(db->config->delete_columns(db, "tableb", &field1, 1));
 
 	stmt = db_prepare_v2(db, SQL("SELECT id, field1a FROM tablea;"));
-	CHECK_MSG(db_query_prepared(stmt), "db_query_prepared must succeed");
+	CHECK_MSG(db_query_prepared_canfail(stmt), "db_query_prepared must succeed");
 	CHECK_MSG(!db_err, "Simple correct SQL command");
 	CHECK(db_step(stmt));
 	CHECK(db_col_u64(stmt, "id") == 0);
@@ -233,7 +233,7 @@ static bool test_manip_columns(void)
 	tal_free(stmt);
 
 	stmt = db_prepare_v2(db, SQL("SELECT id, field2 FROM tableb;"));
-	CHECK_MSG(db_query_prepared(stmt), "db_query_prepared must succeed");
+	CHECK_MSG(db_query_prepared_canfail(stmt), "db_query_prepared must succeed");
 	CHECK_MSG(!db_err, "Simple correct SQL command");
 	CHECK(db_step(stmt));
 	CHECK(db_col_u64(stmt, "id") == 0);
@@ -247,15 +247,15 @@ static bool test_manip_columns(void)
 	db_begin_transaction(db);
 	/* This will actually fail */
 	stmt = db_prepare_v2(db, SQL("SELECT field1 FROM tablea;"));
-	CHECK_MSG(!db_query_prepared(stmt), "db_query_prepared must fail");
+	CHECK_MSG(!db_query_prepared_canfail(stmt), "db_query_prepared must fail");
 	db->dirty = false;
 	db->changes = tal_arr(db, const char *, 0);
 	db_commit_transaction(db);
 
 	db_begin_transaction(db);
 	/* This will actually fail */
 	stmt = db_prepare_v2(db, SQL("SELECT field1 FROM tableb;"));
-	CHECK_MSG(!db_query_prepared(stmt), "db_query_prepared must fail");
+	CHECK_MSG(!db_query_prepared_canfail(stmt), "db_query_prepared must fail");
 	db->dirty = false;
 	db->changes = tal_arr(db, const char *, 0);
 	db_commit_transaction(db);