CODEWITHSUNDEEP
sqljdbcbinaryblobinline
Lukas Eder
Lukas Eder

Reputation: 220762

Inline BLOB / BINARY data types in SQL / JDBC

Let's say I want to avoid using bind variables in JDBC and run SQL using "ad-hoc" statements, e.g:

connection.createStatement().executeQuery("SELECT ...");

Is there any convention / JDBC escape syntax to inline BLOB data types? I know that H2 has this syntax:

INSERT INTO lob_table VALUES (X'01FF');

But that's not a standard. Any general solutions? Note, I'm interested in a general approach. I know that this can turn out to be terribly inefficient.

Upvotes: 12

Views: 12613

Answers (3)

Vadzim
Vadzim

Reputation: 26160

public String binaryLiteral(Connection con, byte[] bytes) {
    String databaseName = con.getMetaData().getDatabaseProductName();
    String binary = DatatypeConverter.printHexBinary(bytes);
    switch (databaseName) {
        case "Microsoft SQL Server":
        case "Sybase Anywhere": case "ASE": case "Adaptive Server Enterprise": // Sybase
            return "CONVERT(VARBINARY(MAX), '0x" + binary + "', 1)";
        case "Oracle":
            if (binary.length() <= 4000) {
                return "HEXTORAW('" + binary + "')";
            } else {
                // https://stackoverflow.com/questions/18116634/oracle-10-using-hextoraw-to-fill-in-blob-data/62162036#62162036
                return "CONCAT_RAWS(RAWS(" +
                        Streams.stream(Splitter.fixedLength(4000).split(binary))
                                .map(chunk -> "HEXTORAW('" + chunk + "')")
                                .collect(Collectors.joining(",")) +
                        "))";
            }
        case "PostgreSQL":
            return "E'\\\\x" + binary + "'";
        case "H2":
        // the following list is mostly untested
        case "HSQL Database Engine":
        case "Apache Derby":
        case "Ingres":
        case "MySQL":
        case "MariaDB":
        case "SQLite":
        case "Informix Dynamic Server":
        case "DB2":
        case "Firebird":
        default: // SQL Standard
            return "X'" + binary + "'";
    }

The source for CONCAT_RAWS and RAWS is given in Oracle 10: Using HEXTORAW to fill in blob data.

Upvotes: 2

Lukas Eder
Lukas Eder

Reputation: 220762

There probably isn't a JDBC escape syntax, so I searched around a bit and found and successfully tested the following:

  • SQL Server, Sybase ASE, Sybase SQL Anywhere

    INSERT INTO lob_table VALUES (0x01FF);

  • DB2

    -- Use a blob constructor. This is not needed for VARCHAR FOR BIT DATA types
INSERT INTO lob_table VALUES (blob(X'01FF'));

  • Derby, H2, HSQLDB, Ingres, MySQL, SQLite

    INSERT INTO lob_table VALUES (X'01FF');

  • Oracle

    -- As mentioned by a_horse_with_no_name, keep in mind the relatively low
-- limitation of Oracle's VARCHAR types to hold only 4000 bytes!
INSERT INTO lob_table VALUES (hextoraw('01FF'));

  • Postgres

    -- There is also hex encoding as of Postgres 9.0
-- The explicit cast is important, though
INSERT INTO lob_table VALUES (E'\\001\\377'::bytea);

    See A.H.'s answer for more details about Postgres' hex encoding

  • SQL Standard

    -- SQL actually defines binary literals as such 
-- (as implemented by DB2, Derby, H2, HSQLDB, Ingres, MySQL, SQLite):
<binary string literal> ::=
  X <quote> [ <space>... ] 
  [ { <hexit> [ <space>... ] <hexit> [ <space>... ] }... ] <quote>

<hexit> ::=
  <digit> | A | B | C | D | E | F | a | b | c | d | e | f

Upvotes: 28

A.H.
A.H.

Reputation: 66243

I'd like to add some PostgreSQL specific stuff to Lukas' answer:

The shortest and most easiest solution would be (since PostgreSQL 9.0 at least): 

insert into lob_table (data) values( E'\\x0102030405FF' )

without any cast (if the column is already a bytea one) and only one \\x mark right at the beginning. This is the "hex format" documented in the section Binary Data Types.

Regarding the X'01FF' syntax: According to the string constant documentation PostgreSQL does support it - for bit strings. And it seems, that there is no standard conversion from bit to bytea.

Upvotes: 4

Related Questions