Oracle Error ORA-06550

Error code

ORA-06550

Product

Oracle Database

Versions

Oracle Database 19c, 21c, 23ai and 26ai (same wording)

Category

PL/SQL & Triggers

Last reviewed

24 October 2026

What it means

ORA-06550 means the PL/SQL block you sent could not be compiled; it gives the line and column of the problem, and the PLS- error on the next line says what the problem is.

Before PL/SQL runs an anonymous block or a call, it compiles it. If compilation fails, nothing in the block runs and Oracle reports each problem as an ORA-06550 line with a position, followed by the compiler's own message. Oracle's reference gives the cause as "usually a PL/SQL compilation error" and the action as: refer to the PL/SQL messages that follow.

So read the line after ORA-06550 first. The most common ones have their own pages: PLS-00201 identifier must be declared, PLS-00103 encountered the symbol (a syntax error) and PLS-00306 wrong number or types of arguments. A second ORA-06550 followed by "PL/SQL: Statement ignored" only says that the statement containing the first error was skipped; it is a consequence, not a second problem. Errors in a SQL statement inside the block are reported the same way, with the SQL error (for example ORA-00942) in place of a PLS- code.

The line and column count from the first line of the block as the database received it, not from the top of your script file. For a stored procedure, package or trigger, compilation happens when you run CREATE; Oracle stores the unit even if it has errors, marks it invalid, and lists the errors in USER_ERRORS. A later call to the invalid unit then fails with ORA-06550 and PLS-00905.

Common causes

• A name the compiler cannot resolve: a misspelt variable, a table or procedure that does not exist or is not visible, or a quoted identifier with the wrong case (PLS-00201).
• A syntax error, such as a missing semicolon, a missing END or THEN, or a reserved word used as a name (PLS-00103).
• A call whose arguments do not match any declaration of the subprogram (PLS-00306).
• An error in a SQL statement embedded in the block, such as a missing table or column, reported by the SQL compiler.
• A call to a stored unit that is invalid because it, or something it depends on, failed to compile (PLS-00905).

Diagnose it

Read-only These queries only read the data dictionary (USER_, ALL_ and DBA_ views) and dynamic performance views (V$). They do not change data, privileges or settings, so they are safe to run first. DBA_ and V$ views need the matching privileges.

SELECT name, type, line, position, attribute, text
FROM all_errors
WHERE owner = 'SHOP'
ORDER BY name, type, sequence;

SELECT object_name, object_type, status, last_ddl_time
FROM all_objects
WHERE owner = 'SHOP'
  AND status = 'INVALID'
ORDER BY object_type, object_name;

SELECT line, text
FROM all_source
WHERE owner = 'SHOP'
  AND name = 'ADD_ORDER'
  AND type = 'PROCEDURE'
  AND line BETWEEN 2 AND 8
ORDER BY line;

SELECT d.referenced_owner, d.referenced_name, d.referenced_type, o.status
FROM all_dependencies d
LEFT JOIN all_objects o
  ON o.owner = d.referenced_owner
 AND o.object_name = d.referenced_name
 AND o.object_type = d.referenced_type
WHERE d.owner = 'SHOP'
  AND d.name = 'ADD_ORDER';

How to fix it

Each fix is labelled with what it changes. Try read-only checks and the least invasive fix first, and test changes outside production.

ALTER PROCEDURE shop.add_order COMPILE;

-- then, in SQL*Plus or SQLcl
SHOW ERRORS PROCEDURE shop.add_order

Examples

A quoted identifier used with the wrong case

Not reproduced here: no Oracle Database is installed for this site. This is the documented example and result from Oracle's PL/SQL Language Reference (lexical units). Double quotation marks make an identifier case-sensitive, so "Hello" is a different name from "HELLO".

DECLARE
  "HELLO" VARCHAR2(10) := 'hello';
BEGIN
  DBMS_OUTPUT.PUT_LINE("Hello");
END;
/

ORA-06550: line 4, column 25:
PLS-00201: identifier 'Hello' must be declared
ORA-06550: line 4, column 3:
PL/SQL: Statement ignored

Calling a procedure that was created with errors

Not reproduced here: no Oracle Database is installed for this site. The message texts are from Oracle's error reference and the layout follows Oracle's PL/SQL examples; the names and positions are illustrative. The real error is in ADD_ORDER itself: SHOW ERRORS or ALL_ERRORS would list PLS-00201 for LOG_ORDER at line 3.

CREATE OR REPLACE PROCEDURE add_order (p_id IN NUMBER) IS
BEGIN
  log_order(p_id);   -- no such procedure
END;
/
-- SQL*Plus: Warning: Procedure created with compilation errors.

BEGIN add_order(1); END;
/

ORA-06550: line 1, column 7:
PLS-00905: object SHOP.ADD_ORDER is invalid
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored

How to prevent it

Check every CREATE of PL/SQL code for errors before moving on: run SHOW ERRORS in your scripts, or query USER_ERRORS in deployment checks, and fail the deployment if any unit is invalid. Create triggers DISABLE first if you need to be sure they compile before they take effect.

Avoid quoted identifiers and reserved words as names, and keep blocks small enough that a line number points to one statement.

Common questions

Learn more on CodeWithSQL

• Stored procedures and functions
• Advanced stored procedures

Official documentation

• ORA-06550 (Oracle Database Error Messages)
• ALL_ERRORS (Oracle Database Reference 19c)
• SHOW, SHOW ERRORS (SQL*Plus User's Guide and Reference 19c)
• Lexical units, identifiers (Oracle PL/SQL Language Reference 19c)

Last technically reviewed 24 October 2026; examples and diagnostics run on Oracle Database Error Messages reference (26ai, 21c and 19c); not run locally. Messages and explanations follow Oracle's Database Error Messages reference; no Oracle Database was available, so the examples were not run locally.