subquery

OCP-1Z0-051 第141题子查询的应用

一、原题 View the Exhibit and examine the structure of CUSTOMERS and GRADES tables. You need to display names and grades of customers who have the highest credit limit. Which two SQL statements would accomplish the task? (Choose two.) A.SELECT custname,…

OCP-1Z0-051 第137题子查询的应用

一、原题 View the Exhibits and examine PRODUCTS and SALES tables. You issue the following query to display product name and the number of times the product has been sold: SQL>SELECT p.prod_name, i.item_cnt FROM (SELECT prod_id, COUNT(*) …

OCP-1Z0-051 第135题子查询注意事项

一、原题 Which three statements are true regarding subqueries? (Choose three.) A. Subqueries can contain GROUP BY and ORDER BY clauses. B. Main query and subquery can get data from different tables. C. Main query and subquery must get data from the same …

OCP-1Z0-051 第140题子查询中使用GROUP BY注意事项

一、原题 Examine the structure of the PRODUCTS table: Name Null Type PROD_ID NOT NULL NUMBER(4) PROD_NAME VARCHAR2(20) PROD_STATUS VARCHAR2(6) QTY_IN_HAND …

OCP-1Z0-051 第133题子查询的用法

一、原题 Which two statements are true regarding subqueries? (Choose two.) A. A subquery can retrieve zero or more rows. B. Only two subqueries can be placed at one level. C. A subquery can be used only in SQL query statements. D. A subquery can appear o…

OCP-1Z0-051 第159题 insert语句中使用子查询

一、原题 View the Exhibit and examine the structure of the CUSTOMERS table. NEW_CUSTOMERS is a new table with the columns CUST_ID, CUST_NAME and CUST_CITY that have the same data types and size as the corresponding columns in the CUSTOMERS table. Evaluat…

OCP-1Z0-051 第125题 self-join（自连接）和self-join(子查询)

一、原题 Examine the structure of the CUSTOMERS table: Name Null Type CUSTNO NOT NULL NUMBER(3) CUSTNAME NOT NULL VARCHAR2(25) CUSTADDRESS VARCHAR2(35) CUST_CREDIT_LIMIT NUMBER…

OCP-1Z0-051 补充题库第8题子查询的使用范围

一、原题 Where can sub queries be used? (Choose all that apply) A. field names in the SELECT statement B. the FROM clause in the SELECT statement C. the HAVING clause in the SELECT statement D. the GROUP BY clause in the SELECT statement E. the WHERE cla…

ORA-00001: 违反唯一约束条件

如何查出违反唯一关键子的类似SQLERRM 有个过程每天更新用户信息表原本采用MERGE 来做的，可是有人嫌它慢，建议采用DELETE INSERT来做我先 delete userinfo wehre logtime > trunc(sysdate)-15 ; commit; insert into userinfo select * fr…

Oracle 1053事件主要看是成本如何计算的?

Apress.Cost.Based.Oracle.Fundamentals. 看中文翻译版看的很吃力. 当初不知10053事件,看完该书花费了很长的时间!10053事件 1 创建测试表 create table zengmuansha_temp01 as select * from dba_objects ; 2 在PL/SQL工具的COMMAND窗口或者SQLPLUS 3 获得会话id:SELECTSYS_C…

oracle复杂查询语句的使用

1.查询语句的使用使用 select语句和子查询(subquery)可以从一个或多个表,视图,实体试图中返回数据.1.1相关子查询可以将子查询(as subquery)或in或exists当成where的一个条件的一部分,这样的查询称为子查询.where中可以包含一个select语句的子查询.where中可以包含in,exists语句…

Oracle Internal Events

Introduction:(简介)有四种类型的Events:Immediate dumpsConditional dumpsTrace dumpsEvents that change database behaviour每一个事件都有一个号跟Oracle的错误信息是一样的.如10046和ORA-10046每一个事件都有一个Level,可以是以下:范围1到10位标 0x01 0x02 0x04 0x08 0x10…

SQL查询命令的语法小结01

查询命令的完整语法： 一．一般语句： Select [all| distinct ] select-list [ from tableView-list ] [where search-condition ] [ group by column-name, ... ] [ having search-condition ] [ order by { expression | integer } [ ASC |D…

OCP-1Z0-051 第166题使用子查询update表中的多列

一、原题 View the Exhibit and examine the structures of the EMPLOYEES and DEPARTMENTS tables. You want to update the EMPLOYEES table as follows: -Update only those employees who work in Boston or Seattle (locations 2900 and 2700). -Set department_id for …

OCP-1Z0-051 第149题子查询中ALL的应用

一、原题 View the Exhibits and examine the structures of the COSTS and PROMOTIONS tables. Evaluate the following SQL statement: SQL>SELECT prod_id FROM costs WHERE promo_id IN (SELECT promo_id FROM promotions …

复杂查询语句的使用,Oracle

############################复杂查询语句的使用#####################################1.查询语句的使用使用 select语句和子查询(subquery)可以从一个或多个表,视图,实体试图中返回数据. 1.1相关子查询可以将子查询(as subquery)或in或exists当成where的一个条件的一部分,这…

OCP-1Z0-051 第142题嵌套子查询的应用

一、原题 View the Exhibit and examine the structure of the PRODUCTS table. Evaluate the following query: SQL> SELECT prod_name FROM products WHERE prod_id IN (SELECT prod_id FROM products WHERE pro…

OCP-1Z0-051 第136题子查询的使用

一、原题 View the Exhibit and examine the structure of the PRODUCTS table. Which two tasks would require subqueries? (Choose two.) A. Display the minimum list price for each product status. B. Display all suppliers whose list price is less than 1000. C.…

OCP-1Z0-051 第168题使用子查询DELETE数据

一、原题 View the Exhibit and examine the description of SALES and PROMOTIONS tables. You want to delete rows from the SALES table, where the PROMO_NAME column in the PROMOTIONS table has either blowout sale or everyday low price as values. Which DELETE …

OCP-1Z0-051 第169题使用子查询DELETE数据

一、原题 View the Exhibit and examine the description for the PRODUCTS and SALES table.PROD_ID is a primary key in the PRODUCTS table and foreign key in the SALES table. You want to remove all the rows from the PRODUCTS table for which no sale was done fo…

OCP-1Z0-051 补充题库第29题 INSERT语句中有子查询

一、原题 View the Exhibit and examine the structure of the CUSTOMERS table. NEW_CUSTOMERS is a new table with the columns CUST_ID, CUST_NAME and CUST_CITY that have the same data types and size as the corresponding columns in the CUSTOMERS table. Evaluat…

OCP-1Z0-051 补充题库第15题子查询和join

一、原题 The COMMISSION column shows the monthly commission earned by the employee. Which two tasks would require sub queries or joins in order to be performed in a single step? (Choose two.) A. listing the employees who earn the same amount of commissi…

ORACLE UPDATE 语句语法与性能分析看法 [转]

update 作者:未知　　 ORACLE UPDATE 语句语法与性能分析的一点看法为了方便起见,建立了以下简单模型,和构造了部分测试数据: 在某个业务受理子系统BSS中， --客户资料表 create table customers ( customer_id number(8) not null, -- 客户标示 cit…

OCP-1Z0-051 第160题 insert中使用子查询

一、原题 View the Exhibit and examine the structure of ORDERS and CUSTOMERS tables. There is only one customer with the cust_last_name column having value Roberts. Which INSERT statement should be used to add a row into the ORDERS table for the customer …

精讲MySQL 数据库的

精讲MySQL 数据库的 SQL 语法参考一、资料定义 ｄｄｌ（data definition language) 　　资料定语言是指对资料的格式和形态下定义的语言，他是每个资料库要建立时候时首先要面对的，举凡资料分哪些表格关系、表格…

OCP-1Z0-051 补充题库第31题 subquery子查询的注意事项

一、原题 Which two statements about sub queries are true? (Choose two.) A. A sub query should retrieve only one row. B. A sub query can retrieve zero or more rows. C. A sub query can be used only in SQL query statements. D. Sub queries CANNOT be nested b…