Oracle Database/SQL Cheatsheet

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This "cheat sheet" covers most of the basic functionality that an Oracle DBA needs to run basic queries and perform basic tasks. It also contains information that a PL/SQL programmer frequently uses to write stored procedures. The resource is useful as a primer for individuals who are new to Oracle, or as a reference for those who are experienced at using Oracle.

A great deal of information about Oracle exists throughout the net. We developed this resource to make it easier for programmers and DBAs to find most of the basics in one place. Topics beyond the scope of a "cheatsheet" generally provide a link to further research.

Other Oracle References

SELECT[edit | edit source]

The SELECT statement is used to retrieve rows selected from one or more tables, object tables, views, object views, or materialized views.

   FROM beverages
   WHERE field1 = 'Kona'
   AND field2 = 'coffee'
   AND field3 = 122;

SELECT INTO[edit | edit source]

Select into takes the values name, address and phone number out of the table employee, and places them into the variables v_employee_name, v_employee_address, and v_employee_phone_number.

This only works if the query matches a single item. If the query returns no rows it raises the NO_DATA_FOUND built-in exception. If your query returns more than one row, Oracle raises the exception TOO_MANY_ROWS.

 SELECT name,address,phone_number
 INTO v_employee_name,v_employee_address,v_employee_phone_number
 FROM employee
 WHERE employee_id = 6;

INSERT[edit | edit source]

The INSERT statement adds one or more new rows of data to a database table.

insert using the VALUES keyword

 INSERT INTO table_name VALUES ('Value1', 'Value2', ... );
 INSERT INTO table_name( Column1, Column2, ... ) VALUES ( 'Value1', 'Value2', ... );

insert using a SELECT statement

 INSERT INTO table_name( SELECT Value1, Value2, ... from table_name );
 INSERT INTO table_name( Column1, Column2, ... ) ( SELECT Value1, Value2, ... from table_name );

DELETE[edit | edit source]

The DELETE statement is used to delete rows in a table.

deletes rows that match the criteria

 DELETE FROM table_name WHERE some_column=some_value
 DELETE FROM customer WHERE sold = 0;

UPDATE[edit | edit source]

The UPDATE statement is used to update rows in a table.

updates the entire column of that table

 UPDATE customer SET state='CA';

updates the specific record of the table eg:

 UPDATE customer SET name='Joe' WHERE customer_id=10;

updates the column invoice as paid when paid column has more than zero.

 UPDATE movies SET invoice='paid' WHERE paid > 0;

SEQUENCES[edit | edit source]

Sequences are database objects that multiple users can use to generate unique integers. The sequence generator generates sequential numbers, which can help automatically generate unique primary keys, and coordinate keys across multiple rows or tables.

CREATE SEQUENCE[edit | edit source]

The syntax for a sequence is:

 CREATE SEQUENCE sequence_name
     MINVALUE value
     MAXVALUE value
     START WITH value
     INCREMENT BY value
     CACHE value;

For example:

 CREATE SEQUENCE supplier_seq
     MAXVALUE 999999999999999999999999999
     CACHE 20;

ALTER SEQUENCE[edit | edit source]

Increment a sequence by a certain amount:

 ALTER SEQUENCE <sequence_name> INCREMENT BY <integer>;
 ALTER SEQUENCE seq_inc_by_ten  INCREMENT BY 10;

Change the maximum value of a sequence:

 ALTER SEQUENCE <sequence_name> MAXVALUE <integer>;

Set the sequence to cycle or not cycle:

 ALTER SEQUENCE <sequence_name> <CYCLE | NOCYCLE>;

Configure the sequence to cache a value:

 ALTER SEQUENCE <sequence_name> CACHE <integer> | NOCACHE;

Set whether or not to return the values in order

 ALTER SEQUENCE <sequence_name> <ORDER | NOORDER>;
 ALTER SEQUENCE seq_order;

Generate query from a string[edit | edit source]

It is sometimes necessary to create a query from a string. That is, if the programmer wants to create a query at run time (generate an Oracle query on the fly), based on a particular set of circumstances, etc.

Care should be taken not to insert user-supplied data directly into a dynamic query string, without first vetting the data very strictly for SQL escape characters; otherwise you run a significant risk of enabling data-injection hacks on your code.

Here is a very simple example of how a dynamic query is done. There are, of course, many different ways to do this; this is just an example of the functionality.

 PROCEDURE oracle_runtime_query_pcd IS
     TYPE ref_cursor IS REF CURSOR;
     l_cursor        ref_cursor;

     v_query         varchar2(5000);
     v_name          varchar2(64);
     v_query := 'SELECT name FROM employee WHERE employee_id=5';
     OPEN l_cursor FOR v_query;
        FETCH l_cursor INTO v_name;
        EXIT WHEN l_cursor%NOTFOUND;
     END LOOP;
     CLOSE l_cursor;

String operations[edit | edit source]

Length[edit | edit source]

Length returns an integer representing the length of a given string. It can be referred to as: length b, length c, length 2, and length 4.

length( string1 );
SELECT length('hello world') FROM dual;
this returns 11, since the argument is made up of 11 characters including the space
SELECT lengthb('hello world') FROM dual;
SELECT lengthc('hello world') FROM dual;
SELECT length2('hello world') FROM dual;
SELECT length4('hello world') FROM dual;
these also return 11, since the functions called are equivalent

Instr[edit | edit source]

Instr (in string) returns an integer that specifies the location of a sub-string within a string. The programmer can specify which appearance of the string they want to detect, as well as a starting position. An unsuccessful search returns 0.

instr( string1, string2, [ start_position ], [ nth_appearance ] )
instr( 'oracle pl/sql cheatsheet', '/');
this returns 10, since the first occurrence of "/" is the tenth character
instr( 'oracle pl/sql cheatsheet', 'e', 1, 2);
this returns 17, since the second occurrence of "e" is the seventeenth character
instr( 'oracle pl/sql cheatsheet', '/', 12, 1);
this returns 0, since the first occurrence of "/" is before the starting point, which is the 12th character

Replace[edit | edit source]

Replace looks through a string, replacing one string with another. If no other string is specified, it removes the string specified in the replacement string parameter.

replace( string1, string_to_replace, [ replacement_string ] );
replace('i am here','am','am not');
this returns "i am not here"

Substr[edit | edit source]

Substr (substring) returns a portion of the given string. The "start_position" is 1-based, not 0-based. If "start_position" is negative, substr counts from the end of the string. If "length" is not given, substr defaults to the remaining length of the string.

substr( string, start_position [, length])

SELECT substr( 'oracle pl/sql cheatsheet', 8, 6) FROM dual;
returns "pl/sql" since the "p" in "pl/sql" is in the 8th position in the string (counting from 1 at the "o" in "oracle")
SELECT substr( 'oracle pl/sql cheatsheet', 15) FROM dual;
returns "cheatsheet" since "c" is in the 15th position in the string and "t" is the last character in the string.
SELECT substr('oracle pl/sql cheatsheet', -10, 5) FROM dual;
returns "cheat" since "c" is the 10th character in the string, counting from the end of the string with "t" as position 1.

Trim[edit | edit source]

These functions can be used to filter unwanted characters from strings. By default they remove spaces, but a character set can be specified for removal as well.

trim ( [ leading | trailing | both ] [ trim-char ] from string-to-be-trimmed );
trim ('   removing spaces at both sides     ');
this returns "removing spaces at both sides"
ltrim ( string-to-be-trimmed [, trimming-char-set ] );
ltrim ('   removing spaces at the left side     ');
this returns "removing spaces at the left side     "
rtrim ( string-to-be-trimmed [, trimming-char-set ] );
rtrim ('   removing spaces at the right side     ');
this returns "   removing spaces at the right side"

DDL SQL[edit | edit source]

Tables[edit | edit source]

Create table[edit | edit source]

The syntax to create a table is:

CREATE TABLE [table name]
      ( [column name] [datatype], ... );

For example:

 CREATE TABLE employee
       (id int, name varchar(20));

Add column[edit | edit source]

The syntax to add a column is:

ALTER TABLE [table name]
      ADD ( [column name] [datatype], ... );

For example:

 ALTER TABLE employee
       ADD (id int);

Modify column[edit | edit source]

The syntax to modify a column is:

ALTER TABLE [table name]
      MODIFY ( [column name] [new datatype] );

ALTER table syntax and examples:

For example:

 ALTER TABLE employee
       MODIFY( sickHours s float );

Drop column[edit | edit source]

The syntax to drop a column is:

ALTER TABLE [table name]
      DROP COLUMN [column name];

For example:

 ALTER TABLE employee
       DROP COLUMN vacationPay;

Constraints[edit | edit source]

Constraint types and codes[edit | edit source]
Type Code Type Description Acts On Level
C Check on a table Column
O Read Only on a view Object
P Primary Key Object
R Referential AKA Foreign Key Column
U Unique Key Column
V Check Option on a view Object
Displaying constraints[edit | edit source]

The following statement shows all constraints in the system:

 FROM user_constraints;
Selecting referential constraints[edit | edit source]

The following statement shows all referential constraints (foreign keys) with both source and destination table/column couples:

      ALL_CONS_COLUMNS c_src,
      ALL_CONS_COLUMNS c_dest
Setting constraints on a table[edit | edit source]

The syntax for creating a check constraint using a CREATE TABLE statement is:

CREATE TABLE table_name
    column1 datatype null/not null,
    column2 datatype null/not null,
    CONSTRAINT constraint_name CHECK (column_name condition) [DISABLE]

For example:

 CREATE TABLE suppliers
     supplier_id  numeric(4),
     supplier_name  varchar2(50),
     CONSTRAINT check_supplier_id
     CHECK (supplier_id BETWEEN 100 and 9999)
Unique Index on a table[edit | edit source]

The syntax for creating a unique constraint using a CREATE TABLE statement is:

CREATE TABLE table_name
    column1 datatype null/not null,
    column2 datatype null/not null,
    CONSTRAINT constraint_name UNIQUE (column1, column2, column_n)

For example:

 CREATE TABLE customer
     id   integer not null,
     name varchar2(20),
     CONSTRAINT customer_id_constraint UNIQUE (id)
Adding unique constraints[edit | edit source]

The syntax for a unique constraint is:

ALTER TABLE [table name]
      ADD CONSTRAINT [constraint name] UNIQUE( [column name] ) USING INDEX [index name];

For example:

 ALTER TABLE employee
       ADD CONSTRAINT uniqueEmployeeId UNIQUE(employeeId) USING INDEX ourcompanyIndx_tbs;
Adding foreign constraints[edit | edit source]

The syntax for a foregin constraint is:

ALTER TABLE [table name]
      ADD CONSTRAINT [constraint name] FOREIGN KEY (column,...) REFERENCES table [(column,...)] [ON DELETE {CASCADE | SET NULL}]

For example:

 ALTER TABLE employee
       ADD CONSTRAINT fk_departament FOREIGN KEY (departmentId) REFERENCES departments(Id);
Deleting constraints[edit | edit source]

The syntax for dropping (removing) a constraint is:[1]

ALTER TABLE [table name]
      DROP CONSTRAINT [constraint name];

For example:

 ALTER TABLE employee
       DROP CONSTRAINT uniqueEmployeeId;

INDEXES[edit | edit source]

An index is a method that retrieves records with greater efficiency. An index creates an entry for each value that appears in the indexed columns. By default, Oracle creates B-tree indexes.

Create an index[edit | edit source]

The syntax for creating an index is:

    ON table_name (column1, column2, . column_n)

UNIQUE indicates that the combination of values in the indexed columns must be unique.

COMPUTE STATISTICS tells Oracle to collect statistics during the creation of the index. The statistics are then used by the optimizer to choose an optimal execution plan when the statements are executed.

For example:

 CREATE INDEX customer_idx
     ON customer (customer_name);

In this example, an index has been created on the customer table called customer_idx. It consists of only of the customer_name field.

The following creates an index with more than one field:

 CREATE INDEX customer_idx
     ON supplier (customer_name, country);

The following collects statistics upon creation of the index:

 CREATE INDEX customer_idx
     ON supplier (customer_name, country)

Create a function-based index[edit | edit source]

In Oracle, you are not restricted to creating indexes on only columns. You can create function-based indexes.

The syntax that creates a function-based index is:

    ON table_name (function1, function2, . function_n)

For example:

 CREATE INDEX customer_idx
     ON customer (UPPER(customer_name));

An index, based on the uppercase evaluation of the customer_name field, has been created.

To assure that the Oracle optimizer uses this index when executing your SQL statements, be sure that UPPER(customer_name) does not evaluate to a NULL value. To ensure this, add UPPER(customer_name) IS NOT NULL to your WHERE clause as follows:

 SELECT customer_id, customer_name, UPPER(customer_name)
 FROM customer
 WHERE UPPER(customer_name) IS NOT NULL
 ORDER BY UPPER(customer_name);

Rename an Index[edit | edit source]

The syntax for renaming an index is:

ALTER INDEX index_name
    RENAME TO new_index_name;

For example:

 ALTER INDEX customer_id
     RENAME TO new_customer_id;

In this example, customer_id is renamed to new_customer_id.

Collect statistics on an index[edit | edit source]

If you need to collect statistics on the index after it is first created or you want to update the statistics, you can always use the ALTER INDEX command to collect statistics. You collect statistics so that oracle can use the indexes in an effective manner. This recalcultes the table size, number of rows, blocks, segments and update the dictionary tables so that oracle can use the data effectively while choosing the execution plan.

The syntax for collecting statistics on an index is:

ALTER INDEX index_name

For example:

 ALTER INDEX customer_idx

In this example, statistics are collected for the index called customer_idx.

Drop an index[edit | edit source]

The syntax for dropping an index is:

   DROP INDEX index_name;

For example:

    DROP INDEX customer_idx;

In this example, the customer_idx is dropped.

DBA Related[edit | edit source]

User Management[edit | edit source]

Creating a user[edit | edit source]

The syntax for creating a user is:

   CREATE USER username IDENTIFIED BY password;

For example:

   CREATE USER brian IDENTIFIED BY brianpass;

Granting privileges[edit | edit source]

The syntax for granting privileges is:

   GRANT privilege TO user;

For example:

   GRANT dba TO brian;

Change password[edit | edit source]

The syntax for changing user password is:

   ALTER USER username IDENTIFIED BY password;

For example:

   ALTER USER brian IDENTIFIED BY brianpassword;

Importing and exporting[edit | edit source]

There are two methods of backing up and restoring database tables and data. The 'exp' and 'imp' tools are simpler tools geared towards smaller databases. If database structures become more complex or are very large ( > 50 GB for example) then using the RMAN tool is more appropriate.

Import a dump file using IMP[edit | edit source]

This command is used to import Oracle tables and table data from a *.dmp file created by the 'exp' tool. Remember that this a command that is executed from the command line through $ORACLE_HOME/bin and not within SQL*Plus.

The syntax for importing a dump file is:

   imp KEYWORD=value

There are number of parameters you can use for keywords.

To view all the keywords:

   imp HELP=yes

An example:

   imp brian/brianpassword FILE=mydump.dmp FULL=yes

PL/SQL[edit | edit source]

Operators[edit | edit source]

Arithmetic operators[edit | edit source]

  • Addition: +
  • Subtraction: -
  • Multiplication: *
  • Division: /
  • Power (PL/SQL only): **
Examples[edit | edit source]

gives all employees from customer id 5 a 5% raise

UPDATE employee SET salary = salary * 1.05
                  WHERE customer_id = 5;

determines the after tax wage for all employees

SELECT wage – tax FROM employee;

Comparison operators[edit | edit source]

  • Greater Than: >
  • Greater Than or Equal To: >=
  • Less Than: <
  • Less Than or Equal to: <=
  • Equivalence: =
  • Inequality: != ^= <> ¬= (depends on platform)
Examples[edit | edit source]
SELECT name, salary, email FROM employees WHERE salary > 40000;
SELECT name FROM customers WHERE customer_id < 6;

String operators[edit | edit source]

  • Concatenate: ||

create or replace procedure addtest( a in varchar2(100), b in varchar2(100), c out varchar2(200) ) IS begin C:=concat(a,'-',b);

Date operators[edit | edit source]

  • Addition: +
  • Subtraction: -

Types[edit | edit source]

Basic PL/SQL Types[edit | edit source]

Scalar type (defined in package STANDARD): NUMBER, CHAR, VARCHAR2, BOOLEAN, BINARY_INTEGER, LONG\LONG RAW, DATE, TIMESTAMP and its family including intervals)

Composite types (user-defined types): TABLE, RECORD, NESTED TABLE and VARRAY

LOB datatypes : used to store an unstructured large amount of data

%TYPE – anchored type variable declaration[edit | edit source]

The syntax for anchored type declarations is

<var_name> <obj>%type [not null][:= <init-val>];

For example

name Books.title%type;   /*  name is defined as the same type as column 'title' of table  Books */
commission number(5,2) := 12.5;
x commission%type;   /*  x is defined as the same type as variable 'commission' */


  1. Anchored variables allow for the automatic synchronization of the type of anchored variable with the type of <obj> when there is a change to the <obj> type.
  2. Anchored types are evaluated at compile time, so recompile the program to reflect the change of <obj> type in the anchored variable.

Collections[edit | edit source]

A collection is an ordered group of elements, all of the same type. It is a general concept that encompasses lists, arrays, and other familiar datatypes. Each element has a unique subscript that determines its position in the collection.

--Define a PL/SQL record type representing a book:
   (title                   book.title%TYPE,
    author                  book.author_last_name%TYPE,
    year_published          book.published_date%TYPE);
--define a PL/SQL table containing entries of type book_rec:
Type book_rec_tab IS TABLE OF book_rec
my_book_rec  book_rec%TYPE;
my_book_rec_tab book_rec_tab%TYPE;
my_book_rec := my_book_rec_tab(5);

There are many good reasons to use collections.

  • Dramatically faster execution speed, thanks to transparent performance boosts including a new optimizing compiler, better integrated native compilation, and new datatypes that help out with number-crunching applications.
  • The FORALL statement, made even more flexible and useful. For example, FORALL now supports nonconsecutive indexes.
  • Regular expressions are available in PL/SQL in the form of three new functions (REGEXP_INSTR, REGEXP_REPLACE, and REGEXP_SUBSTR) and the REGEXP_LIKE operator for comparisons[2].
  • Collections, improved to include such things as collection comparison for equality and support for set operations on nested tables.

References[edit | edit source]

  2. "First Expressions" by Jonathan Gennick for more information in this issue

Stored logic[edit | edit source]

Functions[edit | edit source]

A function must return a value to the caller.

The syntax for a function is

CREATE [OR REPLACE] FUNCTION function_name [ (parameter [,parameter]) ]
RETURN [return_datatype]
    return [return_value]
END [function_name];

For example:

CREATE OR REPLACE  FUNCTION to_date_check_null(dateString IN VARCHAR2, dateFormat IN VARCHAR2)
    IF dateString IS NULL THEN
        return NULL;
        return to_date(dateString, dateFormat);
    END IF;

Procedures[edit | edit source]

A procedure differs from a function in that it must not return a value to the caller.

The syntax for a procedure is:

CREATE [OR REPLACE] PROCEDURE procedure_name [ (parameter [,parameter]) ]
END [procedure_name];

When you create a procedure or function, you may define parameters. There are three types of parameters that can be declared:

  1. IN – The parameter can be referenced by the procedure or function. The value of the parameter can not be overwritten by the procedure or function.
  2. OUT – The parameter can not be referenced by the procedure or function, but the value of the parameter can be overwritten by the procedure or function.
  3. IN OUT – The parameter can be referenced by the procedure or function and the value of the parameter can be overwritten by the procedure or function.

Also you can declare a DEFAULT value;

CREATE [OR REPLACE] PROCEDURE procedure_name [ (parameter [IN|OUT|IN OUT] [DEFAULT value] [,parameter]) ]

The following is a simple example of a procedure:

   /* purpose: shows the students in the course specified by courseId */
   CREATE OR REPLACE Procedure GetNumberOfStudents
      ( courseId IN number, numberOfStudents OUT number )
       /* although there are better ways to compute the number of students,
          this is a good opportunity to show a cursor in action            */
       cursor student_cur is
       select studentId, studentName
           from course
           where course.courseId = courseId;
       student_rec    student_cur%ROWTYPE;
       OPEN student_cur;
           FETCH student_cur INTO student_rec;
           EXIT WHEN student_cur%NOTFOUND;
           numberOfStudents := numberOfStudents + 1;
       END LOOP;
       CLOSE student_cur;
         raise_application_error(-20001,'An error was encountered – '||SQLCODE||' -ERROR- '||SQLERRM);
   END GetNumberOfStudents;

anonymous block[edit | edit source]

 x NUMBER(4) := 0;
  x := 1000;
    x := x + 100;
      x := x + 2;
  x := x + 10;
    x := x + 3;

Passing parameters to stored logic[edit | edit source]

There are three basic syntaxes for passing parameters to a stored procedure: positional notation, named notation and mixed notation.

The following examples call this procedure for each of the basic syntaxes for parameter passing:

CREATE OR REPLACE PROCEDURE create_customer( p_name IN varchar2,
                                             p_id IN number,
                                             p_address IN varchar2,
                                             p_phone IN varchar2 ) IS
    INSERT INTO customer ( name, id, address, phone )
    VALUES ( p_name, p_id, p_address, p_phone );
END create_customer;
Positional notation[edit | edit source]

Specify the same parameters in the same order as they are declared in the procedure. This notation is compact, but if you specify the parameters (especially literals) in the wrong order, the bug can be hard to detect. You must change your code if the procedure's parameter list changes.

create_customer('James Whitfield', 33, '301 Anystreet', '251-222-3154');
Named notation[edit | edit source]

Specify the name of each parameter along with its value. An arrow (=>) serves as the association operator. The order of the parameters is not significant. This notation is more verbose, but makes your code easier to read and maintain. You can sometimes avoid changing code if the procedure's parameter list changes, for example if the parameters are reordered or a new optional parameter is added. Named notation is a good practice to use for any code that calls someone else's API, or defines an API for someone else to use.

create_customer(p_address => '301 Anystreet', p_id => 33, p_name => 'James Whitfield', p_phone => '251-222-3154');
Mixed notation[edit | edit source]

Specify the first parameters with positional notation, then switch to named notation for the last parameters. You can use this notation to call procedures that have some required parameters, followed by some optional parameters.

create_customer(v_name, v_id, p_address=> '301 Anystreet', p_phone => '251-222-3154');

Table functions[edit | edit source]

CREATE TYPE object_row_type as OBJECT (
  object_type VARCHAR(18),
  object_name VARCHAR(30)
CREATE TYPE object_table_type as TABLE OF object_row_type;
  RETURN object_table_type PIPELINED AS
    FOR cur IN (SELECT * FROM all_objects)
      PIPE ROW(object_row_type(cur.object_type, cur.object_name));
SELECT * FROM TABLE(get_all_objects);

Flow control[edit | edit source]

Conditional Operators[edit | edit source]
  • and: AND
  • or: OR
  • not: NOT
Example[edit | edit source]

IF salary > 40000 AND salary <= 70000 THEN() ELSE IF salary>70000 AND salary<=100000 THEN() ELSE()

If/then/else[edit | edit source]

IF [condition] THEN
ELSEIF [condition] THEN
ELSEIF [condition] THEN
ELSEIF [condition] THEN
ELSEIF [condition] THEN
ELSEIF [condition] THEN
ELSEIF [condition] THEN
ELSEIF [condition] THEN

Arrays[edit | edit source]

Associative arrays[edit | edit source]
  • Strongly typed arrays, useful as in-memory tables
Example[edit | edit source]
  • Very simple example, the index is the key to accessing the array so there is no need to loop through the whole table unless you intend to use data from every line of the array.
  • The index can also be a numeric value.
    -- Associative array indexed by string:

    -- Associative array type
    TYPE population IS TABLE OF NUMBER
        INDEX BY VARCHAR2(64);
    -- Associative array variable
    city_population  population;
    i                VARCHAR2(64);
    -- Add new elements to associative array:
    city_population('Smallville')  := 2000;
    city_population('Midland')     := 750000;
    city_population('Megalopolis') := 1000000;

    -- Change value associated with key 'Smallville':
    city_population('Smallville') := 2001;

    -- Print associative array by looping through it:
    i := city_population.FIRST;

            ('Population of ' || i || ' is ' || TO_CHAR(city_population(i)));
        i := city_population.NEXT(i);

    -- Print selected value from a associative array:
    DBMS_OUTPUT.PUT_LINE('Selected value');
    DBMS_OUTPUT.PUT_LINE('Population of');

-- Printed results:
Population of Megalopolis is 1000000
Population of Midland is 750000
Population of Smallville is 2001
  • More complex example, using a record
    -- Record type
    TYPE apollo_rec IS RECORD
        commander   VARCHAR2(100),
        launch      DATE
    -- Associative array type
    TYPE apollo_type_arr IS TABLE OF apollo_rec INDEX BY VARCHAR2(100);
    -- Associative array variable
    apollo_arr apollo_type_arr;
    apollo_arr('Apollo 11').commander := 'Neil Armstrong';
    apollo_arr('Apollo 11').launch :=   TO_DATE('July 16, 1969','Month dd, yyyy');
    apollo_arr('Apollo 12').commander := 'Pete Conrad';
    apollo_arr('Apollo 12').launch :=   TO_DATE('November 14, 1969','Month dd, yyyy');
    apollo_arr('Apollo 13').commander := 'James Lovell';
    apollo_arr('Apollo 13').launch :=   TO_DATE('April 11, 1970','Month dd, yyyy');
    apollo_arr('Apollo 14').commander := 'Alan Shepard';
    apollo_arr('Apollo 14').launch :=   TO_DATE('January 31, 1971','Month dd, yyyy');

    DBMS_OUTPUT.PUT_LINE(apollo_arr('Apollo 11').commander);
    DBMS_OUTPUT.PUT_LINE(apollo_arr('Apollo 11').launch);

-- Printed results:
Neil Armstrong

APEX[edit | edit source]

Oracle Application Express aka APEX, is a web-based software development environment that runs on an Oracle database.

String substitution[edit | edit source]

  • In text: &VARIABLE.

References[edit | edit source]