What does || mean in oracle?

The || operator in Oracle is used to connect two strings, which is equivalent to operators in other languages. It concatenates two string expressions so that if either operand is NULL, the result will also be NULL. The || operator has higher precedence than the operator. In addition to concatenating strings, it can be used to concatenate multiple strings, append strings to variables, and create placeholders.

The meaning of || operator in Oracle

The || operator in Oracle isconnection operator, used to concatenate two strings. It is equivalent to the operator in other programming languages.

Syntax:

<code>expression1 || expression2</code>

Where, expression1 and expression2 are the string expressions to be concatenated.

Example:

<code class="sql">SELECT 'Hello' || 'World' FROM dual;</code>

Output:

<code>HelloWorld</code>

Notes:

• If any If one operand is NULL, the result is NULL.
• || operator has higher precedence than operator, which means that in an expression, || operator will be executed first.
• If you need to convert a non-string type to a string, you can use the TO_CHAR() function.

Other applications:

In addition to concatenating strings, the || operator can also be used for:

• Concatenate multiple strings: 'a' || 'b' || 'c'
• Append a string to an existing variable: my_string := my_string || ' new text'
• Create placeholder: 'column name is ' || my_column (can be used for Dynamic query)

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