SonarSource/sonarqube · error · java.lang.UnsupportedOperationException

Unknown dialect '%s'

Error message

Unknown dialect '%s'

What it means

DecimalColumnDef.generateSqlType maps a migration Dialect to the SQL type string for a DECIMAL/NUMERIC column. It only supports PostgreSQL, Oracle, MsSql and H2; any other dialect id reaches the default branch and throws UnsupportedOperationException "Unknown dialect '%s'". This indicates a migration is being run against an unsupported or unknown database dialect.

Source

Thrown at server/sonar-db-migration/src/main/java/org/sonar/server/platform/db/migration/def/DecimalColumnDef.java:65

  public static Builder newDecimalColumnDefBuilder() {
    return new Builder();
  }

  public int getPrecision() {
    return precision;
  }

  public int getScale() {
    return scale;
  }

  @Override
  public String generateSqlType(Dialect dialect) {
    return switch (dialect.getId()) {
      case PostgreSql.ID, Oracle.ID -> String.format("NUMERIC (%s,%s)", precision, scale);
      case MsSql.ID -> String.format("DECIMAL (%s,%s)", precision, scale);
      case H2.ID -> "DOUBLE";
      default -> throw new UnsupportedOperationException(String.format("Unknown dialect '%s'", dialect.getId()));
    };
  }

  public static class Builder {
    @CheckForNull
    private String columnName;
    private int precision = DEFAULT_PRECISION;
    private int scale = DEFAULT_SCALE;
    private boolean isNullable = true;

    public Builder setColumnName(String columnName) {
      this.columnName = validateColumnName(columnName);
      return this;
    }

    public Builder setIsNullable(boolean isNullable) {
      this.isNullable = isNullable;
      return this;

View on GitHub (pinned to 184c821202)

Solutions

1. Switch sonar.jdbc.url to a supported database: PostgreSQL, Microsoft SQL Server, Oracle, or the embedded H2 (dev only).
2. If you intended a supported DB, verify the dialect detection (sonar.jdbc.driver / URL pattern) so the correct Dialect implementation is resolved.
3. In tests, use one of the registered Dialect constants (PostgreSql.ID, Oracle.ID, MsSql.ID, H2.ID) instead of a custom id.
4. If adding a new dialect, add the corresponding case to DecimalColumnDef.generateSqlType.

Example fix

// before (sonar.properties)
sonar.jdbc.url=jdbc:mysql://db:3306/sonar

// after — supported dialect only
sonar.jdbc.url=jdbc:postgresql://db:5432/sonarqube

Set<String> supported = Set.of(PostgreSql.ID, Oracle.ID, MsSql.ID, H2.ID);
if (!supported.contains(dialect.getId())) {
  throw new IllegalArgumentException("DB engine " + dialect.getId() + " is not supported by SonarQube");
}

try {
  String sql = decimalColumnDef.generateSqlType(dialect);
} catch (UnsupportedOperationException e) {
  throw new IllegalStateException("Configure a supported DB engine (postgres/mssql/oracle/h2)", e);
}

When it happens

Trigger: A database migration generates SQL for a decimal column while dialect.getId() returns an id not in {postgresql, oracle, mssql, h2} — e.g. an unsupported engine or a broken dialect lookup.

Common situations: Pointing SonarQube at a database engine it does not support (MySQL, MariaDB, SQLite) via sonar.jdbc.url; a custom/embedded dialect whose id is unrecognized; unit tests passing a stub Dialect with an unregistered id.

Related errors

• Unsupported dialect id
• Unknown dialect '%s'
• Unsupported dialect id
• Unknown dialect '%s'
• Unsupported dialect id

AI-assisted analysis of SonarSource/sonarqube@184c821202 (2026-09-09). Data as JSON: /api/errors/d4a3f14db9b5e74d. Report an issue: GitHub.