PL/SQL table is a relational object which can store the data by using rows and columns. The columns of the table consist of different attributes or values that you want to store in the table. Each and every individual record consisting of the values of all the attributes or columns is referred to as a row of the table.
What is a table in Oracle Database?
Tables are the basic unit of data storage in an Oracle Database. Data is stored in rows and columns. You define a table with a table name, such as employees , and a set of columns.
What is a table in SQL database?
Tables are database objects that contain all the data in a database. In tables, data is logically organized in a row-and-column format similar to a spreadsheet. Each row represents a unique record, and each column represents a field in the record.
How do you create a table in PL SQL?
The name of the table that you wish to create. The columns that you wish to create in the table. Each column must have a datatype. The column should either be defined as “null” or “not null” and if this value is left blank, the database assumes “null” as the default.
What is PL SQL table and nested table?
Introduction to PL/SQL nested tables
Nested tables are single-dimensional, unbounded collections of homogeneous elements. First, a nested table is single-dimensional, meaning that each row has a single column of data like a one-dimension array. Second, a nested table is unbounded.
What are tables for?
A table is an item of furniture with a raised flat top and is supported most commonly by 1 or 4 legs (although some can have more), used as a surface for working at, eating from or on which to place things.
What are table types in SQL?
The following are the various types of tables in SQL Server.
- User Tables (Regular Tables) Regular tables are the most important tables. …
- Local Temporary Tables. Local temporary tables are the tables stored in tempdb. …
- Global Temporary Tables. …
- Creation of Table with the Help of Another Table. …
- Table Variable.
What is table and field?
A table has records (rows) and fields (columns). Fields have different types of data, such as text, numbers, dates, and hyperlinks. A record: Contains specific data, like information about a particular employee or a product.
What are tables and columns?
Tables contain rows and columns, where the rows are known as records and the columns are known as fields. A column is a set of data values of a particular type (like numbers or alphabets), one value for each row of the database, for example, Age, Student_ID, or Student_Name.
What is table syntax?
A syntax table specifies the syntactic role of each character in a buffer. It can be used to determine where words, symbols, and other syntactic constructs begin and end.
What is a collection in Plsql?
A collection is an ordered group of elements having the same data type. Each element is identified by a unique subscript that represents its position in the collection. PL/SQL provides three collection types − Index-by tables or Associative array.
What is cursor in Plsql?
A cursor is a pointer to this context area. PL/SQL controls the context area through a cursor. A cursor holds the rows (one or more) returned by a SQL statement. The set of rows the cursor holds is referred to as the active set.
What is a record in PL SQL?
A record type is a composite data type that consists of one or more identifiers and their corresponding data types. You can create user-defined record types by using the TYPE IS RECORD statement within a package or by using the CREATE TYPE (Object) statement.
What is type in Plsql?
The %TYPE attribute lets use the datatype of a field, record, nested table, database column, or variable in your own declarations, rather than hardcoding the type names. You can use the %TYPE attribute as a datatype specifier when declaring constants, variables, fields, and parameters.
What is type and Rowtype in Oracle?
%TYPE provides the data type of a variable or a database column to that variable. %ROWTYPE provides the record type that represents a entire row of a table or view or columns selected in the cursor.
Is table of record type?
RECORD and TABLE are user-defined composite types that can be defined by the programmer. The record type allows the defination of a type that consists of specified fields.
What are views in Oracle?
An Oracle view is a validated and named SQL query stored in the Oracle Database’s data dictionary. Views are simply stored queries that can be executed when needed, but they don’t store data. It can be helpful to think of a view as a virtual table, or as the process of mapping data from one or more tables.
What is bulk collection in Oracle PL SQL?
A bulk collect is a method of fetching data where the PL/SQL engine tells the SQL engine to collect many rows at once and place them in a collection. The SQL engine retrieves all the rows and loads them into the collection and switches back to the PL/SQL engine. All the rows are retrieved with only 2 context switches.
How many types of exceptions are there in PL SQL?
There are three types of exceptions: Predefined exceptions are error conditions that are defined by PL/SQL. Non-predefined exceptions include any standard TimesTen errors. User-defined exceptions are exceptions specific to your application.
What is Sqlcode and Sqlerr?
SQLCODE and SQLERRM are Oracle’s built-in error reporting functions in PL/SQL. When an error occurs in PL/SQL at runtime: SQLCODE returns the number of the last encountered error. SQLERRM returns the message associated with its error-number argument.
What is cursor and its types?
Cursor is a Temporary Memory or Temporary Work Station. It is Allocated by Database Server at the Time of Performing DML(Data Manipulation Language) operations on Table by User. Cursors are used to store Database Tables. There are 2 types of Cursors: Implicit Cursors, and Explicit Cursors.
What are triggers in Oracle?
A trigger is either a stored PL/SQL block or a PL/SQL, C, or Java procedure associated with a table, view, schema, or the database itself. Oracle Database automatically executes a trigger when a specified event takes place, which may be in the form of a system event or a DML statement being issued against the table.
What are Joins in Oracle?
A join is a query that combines rows from two or more tables, views, or materialized views. Oracle Database performs a join whenever multiple tables appear in the FROM clause of the query. The select list of the query can select any columns from any of these tables.
What is index in SQL Oracle?
An index is a schema object that contains an entry for each value that appears in the indexed column(s) of the table or cluster and provides direct, fast access to rows. Oracle Database supports several types of index: Normal indexes.
What is limit in bulk collect?
LIMIT clause restricts the number of rows fetched using BULK COLLECT with FETCH statement.
Can we use commit in trigger?
Yes, you can commit inside the trigger. But for this you have to make this trigger transaction to be an Independent transaction from its parent transaction, you can do this by using Pragma. Pragma AUTONOMOUS_TRANSACTION allow you to build the Independent (child) Transaction, started by another.
Which is faster in or exists?
The EXISTS clause is much faster than IN when the subquery results is very large. Conversely, the IN clause is faster than EXISTS when the subquery results is very small. Also, the IN clause can’t compare anything with NULL values, but the EXISTS clause can compare everything with NULLs.