What to use to connect strings in oracle

There are five ways to connect strings in Oracle: 1. Plus sign ( ) operator; 2. CONCAT function; 3. || operator (Oracle 12c and higher); 4. DBMS_LOB.CONCAT Function (LOB data type); 5. Combine INSTR and SUBSTR functions. Choose the most appropriate method based on your needs.

Connecting Strings in Oracle

Oracle provides a variety of ways to connect strings, including:

1. Use the plus sign ( ) operator

The easiest way is to use the plus sign operator ( ) to concatenate strings. For example:

<code>SELECT 'ABC' + 'DEF';</code>

This will return the string "ABCDEF".

2. Use the CONCAT function

The CONCAT function is specially used to connect strings. The syntax is as follows:

<code>CONCAT(string1, string2, ..., stringN)</code>

For example:

<code>SELECT CONCAT('ABC', 'DEF');</code>

will also return the string "ABCDEF".

3. Using the || operator (Oracle 12c and later)

Oracle 12c and later introduces the || operator for strings connect. Its syntax is similar to the plus operator:

<code>string1 || string2 || ... || stringN</code>

For example:

<code>SELECT 'ABC' || 'DEF';</code>

4. Use the DBMS_LOB.CONCAT function

The DBMS_LOB.CONCAT function is used For joining large object (LOB) data types such as CLOB, NCLOB, and BLOB. The syntax is as follows:

<code>DBMS_LOB.CONCAT(lob1, lob2, ..., lobN)</code>

For example:

<code>SELECT DBMS_LOB.CONCAT(CLOB1, CLOB2) FROM table1;</code>

5. Use the INSTR and SUBSTR functions

The INSTR function can return the specified string in another string location in. The SUBSTR function extracts part of a string. These two functions can be used together to concatenate strings. For example:

<code>SELECT SUBSTR('ABCDEF', INSTR('ABCDEF', 'C') + 1);</code>

This will return the string "DEF".

Choose the method that best suits you based on your specific needs.

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