oracle包分为包规范和包体 一:首先创建包规范 create or replace package p_pagewithgroup is -- Author : 肖伟 -- Created : 2014/3/18 -- Purpose : 分组分页过程 TYPE type_cur IS REF CURSOR; --定义游标变量用于返回记录集 PROCEDURE UP_GetRecordWith
oracle包分为包规范和包体
一:首先创建包规范
create or replace package p_pagewithgroup is
-- Author : 肖伟
-- Created : 2014/3/18
-- Purpose : 分组分页过程
TYPE type_cur IS REF CURSOR; --定义游标变量用于返回记录集
PROCEDURE UP_GetRecordWithGroupByPage(
tblName in varchar2, --表名
PageSize in number, --页面大小
PageIndex in number, --当前页
IsReCount out number,--返回总条数
strWhere in varchar2,-- 查询条件 (注意: 不要加 where)
strColums in varchar2, --字段集合,逗号分割
strSelectColums in varchar2, --字段集合,逗号分割
strGroup in varchar2,--分组条件语句
strOrder in varchar2,-- 排序条件语句
v_cur out type_cur --返回当前页数据记录
);
end p_pagewithgroup;
二:创建包结构体
create or replace package body p_pagewithgroup is
PROCEDURE UP_GetRecordWithGroupByPage(
tblName in varchar2, --表名
PageSize in number, --页面大小
PageIndex in number, --当前页
IsReCount out number,--返回总条数
strWhere in varchar2,-- 查询条件 (注意: 不要加 where)
strColums in varchar2, --字段集合,逗号分割
strSelectColums in varchar2, --字段集合,逗号分割
strGroup in varchar2,--分组条件语句
strOrder in varchar2,-- 排序条件语句
v_cur out type_cur --返回当前页数据记录
)
AS
--定义变量
v_sql VARCHAR2(8000);
v_count number;
v_row_start NUMBER; --开始记录
v_row_end NUMBER; --结束记录
begin
------------------------------------------------------------显示总条数
v_sql := 'select count(1) from ' || tblName;
IF strWhere is not NULL OR strWhere ''
THEN
v_sql := v_sql || ' where ' || strWhere;
END IF;
IF strGroup is not null or strGroup ''
then
v_sql := v_sql || ' group by ' || strGroup;
end if;
DBMS_OUTPUT.put_line (v_sql);
--v_sql:='select count(1) from BS_USER where 1=1';
EXECUTE IMMEDIATE v_sql into v_count ;
IsReCount:=v_count;
------------------------------------------------------------显示任意页内容
-- IF PageSize
-- PageSize:=1;
-- END IF;
v_row_start := (PageIndex - 1) * PageSize + 1;
v_row_end := PageIndex * PageSize;
v_sql:='select '||strSelectColums||' from (select t.*,RowNum as rn from (select '||strColums||' from '||tblName;
IF strWhere is not NULL OR strWhere ''
THEN
v_sql := v_sql || ' where ' || strWhere;
END IF;
IF strGroup is not null or strGroup ''
then
v_sql := v_sql || ' group by ' || strGroup;
end if;
IF strOrder is not null or strOrder ''
then
v_sql := v_sql || ' order by ' || strOrder;
end if;
v_sql := v_sql ||') t) where rn between '||v_row_start||' and '||v_row_end;
DBMS_OUTPUT.put_line (v_sql);
open v_cur for v_sql;
End UP_GetRecordWithGroupByPage;
----------------------------------------------------------
end p_pagewithgroup;
三:测试
首先打开PL/SQL command window
SQL>declare
-- Local variables here
IsReCount number;--返回总条数
my_cur p_pagewithgroup.type_cur ; --返回当前页数据记录
begin
-- Test statements here
p_pagewithgroup.UP_GetRecordWithGroupByPage('T_DIVISION',5,1,ISReCount,' 1=1 ',' * ',' * ',null,null,my_cur );
DBMS_OUTPUT.PUT_LINE(TO_CHAR(IsReCount));
end;
,
ACID attributes include atomicity, consistency, isolation and durability, and are the cornerstone of database design. 1. Atomicity ensures that the transaction is either completely successful or completely failed. 2. Consistency ensures that the database remains consistent before and after a transaction. 3. Isolation ensures that transactions do not interfere with each other. 4. Persistence ensures that data is permanently saved after transaction submission.

MySQL is not only a database management system (DBMS) but also closely related to programming languages. 1) As a DBMS, MySQL is used to store, organize and retrieve data, and optimizing indexes can improve query performance. 2) Combining SQL with programming languages, embedded in Python, using ORM tools such as SQLAlchemy can simplify operations. 3) Performance optimization includes indexing, querying, caching, library and table division and transaction management.

MySQL uses SQL commands to manage data. 1. Basic commands include SELECT, INSERT, UPDATE and DELETE. 2. Advanced usage involves JOIN, subquery and aggregate functions. 3. Common errors include syntax, logic and performance issues. 4. Optimization tips include using indexes, avoiding SELECT* and using LIMIT.

MySQL is an efficient relational database management system suitable for storing and managing data. Its advantages include high-performance queries, flexible transaction processing and rich data types. In practical applications, MySQL is often used in e-commerce platforms, social networks and content management systems, but attention should be paid to performance optimization, data security and scalability.

The relationship between SQL and MySQL is the relationship between standard languages and specific implementations. 1.SQL is a standard language used to manage and operate relational databases, allowing data addition, deletion, modification and query. 2.MySQL is a specific database management system that uses SQL as its operating language and provides efficient data storage and management.

InnoDB uses redologs and undologs to ensure data consistency and reliability. 1.redologs record data page modification to ensure crash recovery and transaction persistence. 2.undologs records the original data value and supports transaction rollback and MVCC.

Key metrics for EXPLAIN commands include type, key, rows, and Extra. 1) The type reflects the access type of the query. The higher the value, the higher the efficiency, such as const is better than ALL. 2) The key displays the index used, and NULL indicates no index. 3) rows estimates the number of scanned rows, affecting query performance. 4) Extra provides additional information, such as Usingfilesort prompts that it needs to be optimized.

Usingtemporary indicates that the need to create temporary tables in MySQL queries, which are commonly found in ORDERBY using DISTINCT, GROUPBY, or non-indexed columns. You can avoid the occurrence of indexes and rewrite queries and improve query performance. Specifically, when Usingtemporary appears in EXPLAIN output, it means that MySQL needs to create temporary tables to handle queries. This usually occurs when: 1) deduplication or grouping when using DISTINCT or GROUPBY; 2) sort when ORDERBY contains non-index columns; 3) use complex subquery or join operations. Optimization methods include: 1) ORDERBY and GROUPB


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