FROM_VECTOR

FROM_VECTOR takes a vector as input and returns a string of type VARCHAR2 or CLOB as output.

Syntax

Description of the illustration from_vector.eps

Purpose

FROM_VECTOR optionally takes a RETURNING clause to specify the data type of the returned value.

If VARCHAR2 is specified without size, the size of the returned value size is 32767.

In SQL, you can optionally specify the storage format of the input vector in the FORMAT clause, using the tokens SPARSE or DENSE. The return storage format cannot be specified in PL/SQL; rather, the output format is determined by the storage format of the input vector.

There is no support to convert to CHAR, NCHAR, and NVARCHAR2.

FROM_VECTOR is synonymous with VECTOR_SERIALIZE.

Parameters

expr must evaluate to a vector. The function returns NULL if expr is NULL.

Examples

SELECT FROM_VECTOR(TO_VECTOR('[1, 2, 3]') );

Result:

FROM_VECTOR(TO_VECTOR('[1,2,3]'))

–---------------------------------------------------------------
[1.0E+000,2.0E+000,3.0E+000] 

1 row selected.

SELECT FROM_VECTOR(TO_VECTOR('[1.1, 2.2, 3.3]', 3, FLOAT32) );

Result:

FROM_VECTOR(TO_VECTOR('[1.1,2.2,3.3]',3,FLOAT32))
------------------------------------------------------------------

[1.10000002E+000,2.20000005E+000,3.29999995E+000] 

1 row selected.

SELECT FROM_VECTOR( TO_VECTOR('[1.1, 2.2, 3.3]', 3, FLOAT32) RETURNING VARCHAR2(1000));

Result:

FROM_VECTOR(TO_VECTOR('[1.1,2.2,3.3]',3,FLOAT32)RETURNINGVARCHAR2(1000))
--------------------------------------------------------------------------------

[1.10000002E+000,2.20000005E+000,3.29999995E+000] 

1 row selected.

SELECT FROM_VECTOR(TO_VECTOR('[1.1, 2.2, 3.3]', 3, FLOAT32) RETURNING CLOB );

Result:

FROM_VECTOR(TO_VECTOR('[1.1,2.2,3.3]',3,FLOAT32)RETURNINGCLOB)

--------------------------------------------------------------------------------

[1.10000002E+000,2.20000005E+000,3.29999995E+000] 

1 row selected.

Note:

Applications using Oracle Client 23ai libraries or Thin mode drivers can fetch vector data directly, as shown in the following example:
```
SELECT dataVec FROM vecTab;
```
For applications using Oracle Client 23ai libraries prior to 23ai connected to Oracle Database 23ai, use the FROM_VECTOR to fetch vector data, as shown by the following example:
```
SELECT FROM_VECTOR(dataVec) FROM vecTab;
```

Parent topic: Vector Serializers