hibernate/hibernate-orm · error · IllegalArgumentException

Informix only supports the case insensitive flag 'i' as lite

Error message

Informix only supports the case insensitive flag 'i' as literal but got.

What it means

Informix's regex_match can only be rendered with case-insensitivity toggled; InformixRegexpLikeFunction accepts a third flags argument only when it is the string literal 'i'. Any other flag literal ('c', 'm', 'x', or combinations like 'im') or a non-literal flags argument (bind parameter or expression) makes render() throw IllegalArgumentException before any SQL is generated.

Source

Thrown at hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/function/InformixRegexpLikeFunction.java:38

 */
public class InformixRegexpLikeFunction extends AbstractRegexpLikeFunction {

	public InformixRegexpLikeFunction(TypeConfiguration typeConfiguration) {
		super( typeConfiguration );
	}

	@Override
	public void render(
			SqlAppender sqlAppender,
			List<? extends SqlAstNode> arguments,
			ReturnableType<?> returnType,
			SqlAstTranslator<?> walker) {
		final boolean caseSensitive;
		if ( arguments.size() > 2 ) {
			if ( !(arguments.get( 2 ) instanceof Literal literal)
				|| !(literal.getLiteralValue() instanceof String flags)
				|| !flags.equals( "i" ) ) {
				throw new IllegalArgumentException( "Informix only supports the case insensitive flag 'i' as literal but got." );
			}
			caseSensitive = false;
		}
		else {
			caseSensitive = true;
		}

		sqlAppender.appendSql( "regex_match(" );
		arguments.get( 0 ).accept( walker );
		sqlAppender.appendSql( ',' );
		arguments.get( 1 ).accept( walker );
		if ( !caseSensitive ) {
			// 1 is extended POSIX regex which is the default, 3 is extended POSIX regex and case-insensitive
			// See https://www.ibm.com/docs/en/informix-servers/14.10.0?topic=routines-regex-match-function
			sqlAppender.appendSql( ",3" );
		}
		sqlAppender.appendSql( ')' );
	}

View on GitHub (pinned to fad1729dce)

Solutions

1. Pass only the literal 'i' when case-insensitive matching is needed, or omit the third argument entirely
2. Encode case-sensitivity in the pattern itself (character classes like [a-zA-Z]) instead of flags
3. Build per-dialect HQL variants so Informix never receives unsupported flags
4. Use a native query when richer flags are genuinely required

Example fix

// before
:flags bound as parameter
List<E> l = em.createQuery("select e from E e where regexp_like(e.code, :pat, :flags)", E.class)
    .setParameter("pat", "^abc").setParameter("flags", "i").getResultList();

// after: literal 'i' only (or drop the argument for case-sensitive)
List<E> l = em.createQuery("select e from E e where regexp_like(e.code, :pat, 'i')", E.class)
    .setParameter("pat", "^abc").getResultList();

// Validate the flags argument before binding it into HQL for Informix
static String informixFlags(String flags) {
    if (flags == null || flags.isEmpty()) return null;       // case-sensitive default
    if ("i".equals(flags)) return "'i'";                     // only supported literal
    throw new IllegalArgumentException("Informix regexp_like supports only literal flag 'i'");
}

try {
    return em.createQuery(hql, E.class).setParameter("flags", flags).getResultList();
} catch (IllegalArgumentException e) {
    if (e.getMessage() != null && e.getMessage().contains("case insensitive flag")) {
        // drop the flags parameter or hardcode 'i' and rebuild the query
    }
    throw e;
}

When it happens

Trigger: HQL `regexp_like(e.name, '^abc', 'c')`, combined flags like 'im', or a bound flags parameter (`regexp_like(e.name, :pat, :flags)`) with InformixDialect. Two-argument calls work fine.

Common situations: Reusable query fragments shared across databases where other dialects accept the full flag set; dynamic queries that bind flags as a parameter to avoid recompiling.

Related errors

• Informix does not support binary literals
• Connection lock-timeout does not accept skip-locked
• Can't emulate offset clause in subquery
• Summarization is not supported by DBMS!
• Insert conflict 'do update' clause with constraint name is n

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/f9c9c438e421f03d. Report an issue: GitHub.