PowerDesigner导出SQL,导入到Oracle中查询表结构报“ORA-04043:
环境 Oracle 11.2.0 SQL Plus PowerDesigner 15.1 问题 这学期学习Oracle数据库应用技术,需要做一个课程设计。PowerDesigner导出SQL,导入到Oracle中查询表结构报“ORA-04043: 对象XXX不存在”错误。 解决 查询表结构时加上双引号。 总结 工具自动生成的SQL
环境
Oracle 11.2.0 + SQL Plus + PowerDesigner 15.1
问题
这学期学习Oracle数据库应用技术,需要做一个课程设计。PowerDesigner导出SQL,导入到Oracle中查询表结构报“ORA-04043: 对象XXX不存在”错误。
解决
查询表结构时加上双引号。
总结
工具自动生成的SQL会有些问题,所以我是不建议使用工具自动生成的,手写才是保证万无一失的最好方法。
操作日志
G:\编程资料\Learning\数据库应用技术 Oracle\实验\实验五>sqlplus wgb SQL*Plus: Release 11.2.0.1.0 Production on 星期二 6月 11 09:07:05 2013 Copyright (c) 1982, 2010, Oracle. All rights reserved. 输入口令: 连接到: Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production With the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> SELECT * from tab; TNAME TABTYPE CLUSTERID ------------------------------ ------- ---------- tb_class TABLE tb_course TABLE tb_score TABLE tb_select TABLE TNAME TABTYPE CLUSTERID ------------------------------ ------- ---------- tb_student TABLE tb_teacher TABLE tb_user TABLE 已选择7行。 SQL> DESC tb_class; ERROR: ORA-04043: 对象 tb_class 不存在 SQL> DESC tb_course; ERROR: ORA-04043: 对象 tb_course 不存在 SQL> DESCRIBE tb_class; ERROR: ORA-04043: 对象 tb_class 不存在 SQL> SELECT * from tb_class 2 ; SELECT * from tb_class * 第 1 行出现错误: ORA-00942: 表或视图不存在 SQL> DESC "tb_class"; 名称 是否为空? 类型 ----------------------------------------- -------- ---------------------------- n_teacher_id1 NUMBER(8) n_student_id NUMBER(8) n_class_id NOT NULL NUMBER(8) vc_class_name NOT NULL VARCHAR2(40) vc_class_col NOT NULL VARCHAR2(30) n_course_teacher_id NOT NULL NUMBER(8)
参考资料
http://blog.csdn.net/bupt_zoucq/article/details/6712198
<span><span>我的邮箱</span></span><span>:</span>wgbno27@163.com <span> <span>新浪微博</span></span><span>:</span>@Wentasy27 <span>微信公众平台</span>:JustOracle(微信号:justoracle) <span>数据库技术交流群</span>:336882565(加群时验证 From CSDN XXX) <span>Oracle交流讨论组</span>:https://groups.google.com/d/forum/justoracle <span><strong>By Larry Wen</strong></span>
![]() |
![]() ![]() |
@Wentasy |

MySQL is an open source relational database management system, mainly used to store and retrieve data quickly and reliably. Its working principle includes client requests, query resolution, execution of queries and return results. Examples of usage include creating tables, inserting and querying data, and advanced features such as JOIN operations. Common errors involve SQL syntax, data types, and permissions, and optimization suggestions include the use of indexes, optimized queries, and partitioning of tables.

MySQL is an open source relational database management system suitable for data storage, management, query and security. 1. It supports a variety of operating systems and is widely used in Web applications and other fields. 2. Through the client-server architecture and different storage engines, MySQL processes data efficiently. 3. Basic usage includes creating databases and tables, inserting, querying and updating data. 4. Advanced usage involves complex queries and stored procedures. 5. Common errors can be debugged through the EXPLAIN statement. 6. Performance optimization includes the rational use of indexes and optimized query statements.

MySQL is chosen for its performance, reliability, ease of use, and community support. 1.MySQL provides efficient data storage and retrieval functions, supporting multiple data types and advanced query operations. 2. Adopt client-server architecture and multiple storage engines to support transaction and query optimization. 3. Easy to use, supports a variety of operating systems and programming languages. 4. Have strong community support and provide rich resources and solutions.

InnoDB's lock mechanisms include shared locks, exclusive locks, intention locks, record locks, gap locks and next key locks. 1. Shared lock allows transactions to read data without preventing other transactions from reading. 2. Exclusive lock prevents other transactions from reading and modifying data. 3. Intention lock optimizes lock efficiency. 4. Record lock lock index record. 5. Gap lock locks index recording gap. 6. The next key lock is a combination of record lock and gap lock to ensure data consistency.

The main reasons for poor MySQL query performance include not using indexes, wrong execution plan selection by the query optimizer, unreasonable table design, excessive data volume and lock competition. 1. No index causes slow querying, and adding indexes can significantly improve performance. 2. Use the EXPLAIN command to analyze the query plan and find out the optimizer error. 3. Reconstructing the table structure and optimizing JOIN conditions can improve table design problems. 4. When the data volume is large, partitioning and table division strategies are adopted. 5. In a high concurrency environment, optimizing transactions and locking strategies can reduce lock competition.

In database optimization, indexing strategies should be selected according to query requirements: 1. When the query involves multiple columns and the order of conditions is fixed, use composite indexes; 2. When the query involves multiple columns but the order of conditions is not fixed, use multiple single-column indexes. Composite indexes are suitable for optimizing multi-column queries, while single-column indexes are suitable for single-column queries.

To optimize MySQL slow query, slowquerylog and performance_schema need to be used: 1. Enable slowquerylog and set thresholds to record slow query; 2. Use performance_schema to analyze query execution details, find out performance bottlenecks and optimize.

MySQL and SQL are essential skills for developers. 1.MySQL is an open source relational database management system, and SQL is the standard language used to manage and operate databases. 2.MySQL supports multiple storage engines through efficient data storage and retrieval functions, and SQL completes complex data operations through simple statements. 3. Examples of usage include basic queries and advanced queries, such as filtering and sorting by condition. 4. Common errors include syntax errors and performance issues, which can be optimized by checking SQL statements and using EXPLAIN commands. 5. Performance optimization techniques include using indexes, avoiding full table scanning, optimizing JOIN operations and improving code readability.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

SublimeText3 Chinese version
Chinese version, very easy to use

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function