In fact, you must separate adjacent identifiers by a space or punctuation.
The following line is not allowed because the reserved words A delimiter is a simple or compound symbol that has a special meaning to PL/SQL.
A line of PL/SQL text contains groups of characters known as lexical units: To improve readability, you can separate lexical units by spaces.
Internally, they are both represented by a zero representing the string length and nothing else.
Depending on what you do with it, Oracle treats a NULL character string as '' or NULL, as it deems fit: Originally posted by cmasharma Ok. when the comparison of col is done in where clause, the 2 rows get selected when compared with null and not with '' 2.
Data validate rules can be enforced within your application code in the application layer; or data can be validated by the database engine.
Depending on your validation, rule requirement will determine where and how you will need to build your application to ensure your data is properly validated.
For example, you use delimiters to represent arithmetic operations such as addition and subtraction. An identifier consists of a letter optionally followed by more letters, numerals, dollar signs, underscores, and number signs.