Oracle - Cannot update table record using bind variable - oracle

Question

This query returns 1 row:
SELECT col1, col2 FROM table1 WHERE col1 = :column1;
But this updates 0 rows:
UPDATE table1 SET col2 = :column2 WHERE col1 = :column1;
COMMIT;
I added this constraint to set col1 as primary key, but it didn't fix it.
ALTER TABLE table1 ADD CONSTRAINT col1_pk PRIMARY KEY (col1);
I am trying this from SQL Developer, any idea why it does not update the row?
EDIT:
col1 is VARCHAR2(32 BYTE) NOT NULL
col2 is CLOB NOT NULL
EDIT 2: Test Case, set :var1 to 0011223344556677 in the select and update sentences.
CREATE TABLE MY_TABLE
( COL1 VARCHAR2(32 BYTE) NOT NULL ENABLE,
COL2 CLOB,
CONSTRAINT "MY_TABLE_PK" PRIMARY KEY ("COL1")
)
INSERT INTO MY_TABLE (COL1, COL2) VALUES ('0011223344556677', '1434407992143440799214344079921434407992');
SELECT * FROM MY_TABLE WHERE COL1 = :var1;
UPDATE MY_TABLE SET COL2 = 'test' WHERE COL1 = :var1;
COMMIT;

Answer 1

TL;DR - Make sure the value being stored in the bind variable is parsed as a character string not a number.
I've run this in SQL Developer (Version 4.0.3.16):
CREATE TABLE MY_TABLE
( COL1 VARCHAR2(32 BYTE) NOT NULL ENABLE,
COL2 CLOB,
CONSTRAINT "MY_TABLE_PK" PRIMARY KEY ("COL1")
);
/
INSERT INTO MY_TABLE (COL1, COL2) VALUES ('0011223344556677', '1434407992143440799214344079921434407992');
/
VARIABLE var1 VARCHAR2(32);
/
BEGIN
:var1 := '0011223344556677';
END;
/
SELECT * FROM MY_TABLE WHERE COL1 = :var1;
/
UPDATE MY_TABLE SET COL2 = 'test' WHERE COL1 = :var1;
/
COMMIT;
/
SELECT * FROM MY_TABLE;
/
And it runs fine:
table MY_TABLE created.
1 rows inserted.
anonymous block completed
COL1 COL2
-------------------------------- --------------------------------------------------------------------------------
0011223344556677 1434407992143440799214344079921434407992
1 rows updated.
committed.
COL1 COL2
-------------------------------- --------------------------------------------------------------------------------
0011223344556677 test
If you change the variable assignment to (remove quotes):
BEGIN
:var1 := 0011223344556677;
END;
Then the value is parsed as a number and the leading zeros are ignored and the output is:
table MY_TABLE created.
1 rows inserted.
anonymous block completed
no rows selected
0 rows updated.
committed.
COL1 COL2
-------------------------------- --------------------------------------------------------------------------------
0011223344556677 1434407992143440799214344079921434407992