[, ...] ) = [ ROW ] ( { expression | DEFAULT } [, ...] ) | ( column_name [, ...] ) = ( sub-SELECT ) } [, ...] [ FROM from_item [, ...] ] [ WHERE condition | WHERE CURRENT OF cursor_name ] [ RETURNING * | output_expression [ [ AS ] output_name ] [, ....
Because variable substitution is done on a bound cursor’s query, there are really two ways to pass values into the cursor: either with an explicit argument to OPEN, or implicitly by referencing a PL/pgSQL variable in the query. For example, another way to get the same effect as the cur...
Because variable substitution is done on a bound cursor’s query, there are really two ways to pass values into the cursor: either with an explicit argument to OPEN, or implicitly by referencing a PL/pgSQL variable in the query. For example, another way to get the same effect as the cur...
on、off 或 partition #cursor_tuple_fraction = 0.1 # 设置计划器对将要检索的游标行的比例的估计值 范围 0.0-1.0 #from_collapse_limit = 8 #jit = on # 允许 JIT 编译#join_collapse_limit = 8 # 1 禁用显式 JOIN 子句的折叠 #plan_cache_mode = auto # auto、force_generic_plan 或 force_...
UPDATE, INSERT, and DELETE statements set FOUND true if at least one row is affected, false if no row is affected. A FETCH statement sets FOUND true if it returns a row, false if no row is returned. A MOVE statement sets FOUND true if it successfully repositions the cursor, false othe...
your_email@example.com'receiver_email='admin@example.com'# 执行时间阈值threshold=1000# 单位:毫秒try:# 连接数据库conn=psycopg2.connect(**db_params)cursor=conn.cursor()# 查询触发器函数的执行时间query=f"SELECT total_time FROM pg_stat_statements WHERE query LIKE '%update_stock%'"cursor.execute(...
# Python 示例 import mysql.connector from mysql.connector import errors try: cursor.execute("UPDATE accounts SET balance = balance - 100 WHERE user_id = 1") except errors.DatabaseError as e: if 'Deadlock' in str(e): print("检测到死锁,正在重试...") # 重试逻辑 ...
UPDATE users SET email = 'new@example.com' WHERE id = 1; -- 删除数据 DELETE FROM users WHERE id = 2; 事务操作 try: cursor.execute("BEGIN TRANSACTION") cursor.execute("INSERT INTO logs (message) VALUES ('Operation start')") cursor.execute("COMMIT") ...
import pyodbc server='tcp:myserver.database.windows.net'database='exampledb'username='exampleusername'password='examplepassword'conn=pyodbc.connect('DRIVER={ODBC Driver 17 for SQL Server};SERVER='+server+';DATA...
Added comprehensive cursor state cleanup to avoid stale data in case of connection pooling. Fixed a issue with IDENTITY columns not being recognized during DML statements using OUTPUT and WHERE clause. High Priority stability enhancements Fixed an issue where @@function in UPDATE SET clause causes sy...