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SQL-3 is short for Structured Query Language Level 3, which is a standard that defines the syntax and semantics of SQL queries. It includes features like advanced outer joins, enhanced data manipulation capabilities, and support for recursive queries. SQL-3 builds upon SQL-92 and provides more advanced functionality for managing databases.
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What is the difference between eclipse ide and netbeans IDE?
BASIC DIFFERENCENetbeans:1. Tool based IDE2. Inbuilt support for SQL3. Good for the beginnersEclipse:1. Plugin Based IDE2. Inbulit JDBC driver support but takes time to configure3. Used for the professional
Explain the various data types available in SQL?
You retrieve, store, and update SQL3 datatypes the same way you do other datatypes. You use either ResultSet. getXXX or CallableStatement. getXXX methods to retrieve them, PreparedStatement. setXXX methods to store them, and updateXXX to update them. Probably 90 percent of the operations performed on SQL3 types involve using the getXXX , setXXX , and updateXXX methods. The following table shows which methods to use: SQL3 type getXXX method setXXX method updateXXX methodBLOB getBlob setBlob updateBlobCLOB getClob setClob updateClobARRAY getArray setArray updateArrayStructured type getObject setObject updateObjectREF (structured type) getRef setRef updateRef For example, the following code fragment retrieves an SQL ARRAY value. For this example, the column SCORES in the table STUDENTS contains values of type ARRAY . The variable stmt is a Statement object. ResultSet rs = stmt.executeQuery( "SELECT SCORES FROM STUDENTS WHERE ID = 2238"); rs.next(); Array scores = rs.getArray("SCORES"); The variable scores is a logical pointer to the SQL ARRAY object stored in the table STUDENTS in the row for student 2238. If you want to store a value in the database, you use the appropriate setXXX method. For example, the following code fragment, in which rs is a ResultSet object, stores a Clob object: Clob notes = rs.getClob("NOTES"); PreparedStatement pstmt = con.prepareStatement( "UPDATE MARKETS SET COMMENTS = ? WHERE SALES < 1000000", ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE); pstmt.setClob(1, notes); This code sets notes as the first parameter in the update statement being sent to the database. The CLOB value designated by notes will be stored in the table MARKETS in column COMMENTS in every row where the value in the column SALES is less than one million
What is post relational data model?
A number of extensions to the relational data model have been proposed in the three decades or so since its invention. Many of these extensions have been implemented in commercial DBMS. What is termed the post-relational data model here is not strictly a data model in that no coherent theory has been developed. Nevertheless it is useful to discuss it here in terms of a set of mech- anisms found in many contemporary DBMS. Such a data model is also referred to by the terms extended-relational and object-relational data model. In Chapter 18 we discuss how the proposed SQL3 standard addresses many of these features. In Chapter 34 we also consider how the ORACLE DBMS supports some of these features. In the first half of the chapter we consider two extensions to the data defin- ition part of the relational data model: abstract data types and nested relations. In the second half of the chapter we consider two constructs - triggers and stored procedures - that have been used both for data manipulation and data integrity purposes. The incorporation of these features into a relational DBMS provides it with the ability to handle complex objects and behaviour. Hence many of the DBMS with these features have termed themselves object-rela- tional systems.
Compare oodbms with rdbms?
The differences between the three approaches Table 1: A Comparison of Database Management Systems Criteria RDBMS ODBMS ORDBMS Defining standard SQL2 ODMG-2.0 SQL3 (in process) Support for object-oriented features Does not support; It is difficult to map program object to the database Supports extensively Limited support; mostly to new data types Usage Easy to use OK for programmers; some SQL access for end users Easy to use except for some extensions Support for complex relationships Does not support abstract datatypes Supports a wide variety of datatypes and data with complex inter-relationships Supports Abstract datatypes and complex relationships Performance Very good performance Relatively less performance Expected to perform very well Product maturity Relatively old and so very mature This concept is few years old and so relatively mature Still in development stage so immature. The use of SQL Extensive supports SQL OQL is similar to SQL, but with additional features like Complex objects and object-oriented features. SQL3 is being developed with OO features incorporated in it Advantages Its dependence on SQL, relatively simple query optimization hence good performance It can handle all types of complex applications, reusability of code, less coding Ability to query complex applications and ability to handle large and complex applications Disadvantages Inability to handle complex applications Low performance due to complex query optimization, inability to support large-scale systems Low performance in web applications Support from vendors It is considered to be highly successful so the market size is very large but many vendors are moving towards ORDBMS Presently lacking vendor support due to vast size of RDBMS market All major RDBMS vendors are after this so has very good future
