Merge data from a csv file into Oracle

Question

I have a php script that inserts data from a csv file into an Oracle table :

$handle = fopen('file.txt', "r");
for($i =1;($data = fgetcsv($handle, 10000, ";")) !== FALSE; $i++) {
// The query uses placeholders for data
$sql = "INSERT INTO table
                (col1,col2,col3,col4)
            VALUES
                (:val1,:val2,:val3,:val4)";
$sth = $conn->prepare($sql);

// The data is bound to the placeholders
$sth->bindParam(':val1', $data[0]);
$sth->bindParam(':val2', $data[1]);
$sth->bindParam(':val3', $data[2]);
$sth->bindParam(':val4', $data[3]);

// The row is actually inserted here
$sth->execute();
$sth->closeCursor();

Now i'm trying to replace the insert with a merge so I can do an isert only if the data does not exist already.

I took a look at some SO questions and the Oracle documentation, but still can't figure that out (without using procedures, whice is all i found...)

can you please help ?

Answer 1

In your case, if you only want to do an INSERT then you don't need to use MERGE . If you have proper constraints defined on the table , then you don't have to worry about validating the existing rows in the table.

Anyway, as per your comments to the question, you want to use MERGE . So, here are few examples of the [optional] MATCHED and NOT MATCHED clauses valid for releases 10g and up:

Both clauses present

MERGE INTO test1 a
  USING (SELECT :val1,:val2,:val3,:val4 FROM DUAL) b
    ON (a.key = b.key) -- put the required join key
  WHEN MATCHED THEN
    UPDATE SET a.col = b.col
  WHEN NOT MATCHED THEN
    INSERT (col1,col2,col3,col4)
    VALUES (b.object_id, b.status);

No matched clause, insert only

MERGE INTO test1 a
  USING (SELECT :val1,:val2,:val3,:val4 FROM DUAL) b
    ON (a.key = b.key) -- put the required join key
  WHEN NOT MATCHED THEN
    INSERT (col1,col2,col3,col4)
    VALUES (b.object_id, b.status);

No not-matched clause, update only

MERGE INTO test1 a
  USING (SELECT :val1,:val2,:val3,:val4 FROM DUAL) b
    ON (a.key = b.key) -- put the required join key
  WHEN MATCHED THEN
    UPDATE SET a.col = b.col;

See some usage examples here .