如何在postgreSQL中创建物化视图日志?我在给定的查询中遇到语法错误

在PostgreSQL中创建物化视图日志的过程如下：

首先，创建物化视图：

CREATE MATERIALIZED VIEW my_materialized_view AS
SELECT column1, column2, ...
FROM table1
WHERE condition;

接下来，创建用于记录物化视图日志的表：

CREATE TABLE my_materialized_view_log (
    timestamp timestamp DEFAULT current_timestamp,
    event_type text,
    details jsonb
);

然后，使用触发器在物化视图上捕获变更事件，并将事件记录到日志表中：

CREATE OR REPLACE FUNCTION log_materialized_view_changes()
RETURNS TRIGGER AS $$
BEGIN
    IF TG_OP = 'INSERT' THEN
        INSERT INTO my_materialized_view_log (event_type, details)
        VALUES ('insert', row_to_json(NEW));
    ELSIF TG_OP = 'UPDATE' THEN
        INSERT INTO my_materialized_view_log (event_type, details)
        VALUES ('update', row_to_json(NEW));
    ELSIF TG_OP = 'DELETE' THEN
        INSERT INTO my_materialized_view_log (event_type, details)
        VALUES ('delete', row_to_json(OLD));
    END IF;
    RETURN NULL;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER trigger_log_materialized_view_changes
AFTER INSERT OR UPDATE OR DELETE ON my_materialized_view
FOR EACH ROW EXECUTE FUNCTION log_materialized_view_changes();

最后，通过查询日志表可以查看物化视图的变更历史：