SQL

How to Resolve ORA-01722: invalid number

by Ed Chen
January 22, 2020January 31, 2020

ORA-01722 ORA-01722 means that the arithmetic operation in the statement failed to calculate because one of operands cannot be converted to a valid number implicitly.… Read More »

How to Resolve ORA-01400: cannot insert NULL into

by Ed Chen
November 27, 2019January 17, 2020

ORA-01400 ORA-01400 means that there's a column which was found as NOT NULL is not listed in the INSERT statement, you have to provide a… Read More »

Oracle TO_DATE Function Examples

by Ed Chen
September 21, 2019December 24, 2019

Oracle TO_DATE Oracle TO_DATE function can convert a date time string into a value acceptable for converting string into datetime type. There're 4 major components… Read More »

How to Take Backup of Stored Procedure in Oracle

by Ed Chen
September 11, 2019November 8, 2019

Backup of Stored Procedure Usually, source codes of programming unit should be version-controlled by the developer team. But if they have never carried out their… Read More »

Oracle SUBSTR Function Examples

by Ed Chen
August 21, 2019October 24, 2019

Oracle SUBSTR Examples Oracle SUBSTR function is used to cut or extract a piece of sub-string from an outer string. In this post, I will… Read More »

How to Resolve PLS-00103: Encountered the symbol when expecting one of the

by Ed Chen
June 14, 2019November 4, 2019

PLS-00103 I cannot cover all error patterns of PL-00103 in this post, here is one case that encounter PLS-00103 in anonymous PL/SQL block using EXECUTE… Read More »

ORA-06502 due to Character Type Conversion

How to Resolve ORA-06502: PL/SQL: numeric or value error: character to number conversion error

by Ed Chen
May 26, 2019January 31, 2020

ORA-06502 ORA-06502 means that PL/SQL engine cannot convert a character-typed string into a number or a subset of arithmetic for overall evaluation. Mostly, it's because… Read More »

How to Resolve ORA-01861: literal does not match format string

by Ed Chen
May 17, 2019February 20, 2020

ORA-01861 ORA-01861 means that the format strings of DATE and CHAR between two operands are not comparable literally, we should make them match with each… Read More »

How to Revert INSERT INTO by DELETE FROM Statements

by Ed Chen
April 26, 2019November 29, 2019

Revert INSERT INTO Suppose that you have created two rows by INSERT INTO statements like this: SQL> INSERT INTO HR.EMPLOYEES (EMPLOYEE_ID, LAST_NAME, EMAIL, HIRE_DATE, JOB_ID)… Read More »

How to Resolve ORA-00903: invalid table name

by Ed Chen
March 28, 2019June 2, 2019

In this post, I will introduce 3 main error patterns about ORA-00903, they are: Violating Naming Rules Missing Quotes Incorrect Syntax ORA-00903 due to Violating… Read More »