flowable/flowable-engine · error · TypeException

Error setting null for parameter #${i} with JdbcType ${jdbcT

Error message

Error setting null for parameter #${i} with JdbcType ${jdbcType} . Try setting a different JdbcType for this parameter or a different jdbcTypeForNull configuration property. Cause: ${e}

What it means

TypeException raised when ps.setNull(...) fails for a nullable String parameter in FlowableStringTypeHandler.setParameter. The handler already had a JdbcType but the driver rejected the setNull call; the message suggests choosing a different JdbcType or changing the jdbcTypeForNull configuration.

Source

Thrown at modules/flowable-engine-common/src/main/java/org/flowable/common/engine/impl/db/FlowableStringTypeHandler.java:41

        if (parameter == null) {
            if (jdbcType == null) {
                throw new TypeException("JDBC requires that the JdbcType must be specified for all nullable parameters.");
            }
            try {
                if (useDefaultJdbcType) {
                    JdbcType finalJdbcType = null;
                    if (jdbcType.equals(JdbcType.NVARCHAR)) {
                        finalJdbcType = JdbcType.VARCHAR;
                    } else {
                        finalJdbcType = jdbcType;
                    }
                    ps.setNull(i,  finalJdbcType.TYPE_CODE);
                    
                } else {
                    ps.setNull(i, Types.NULL);
                }
            } catch (SQLException e) {
                throw new TypeException("Error setting null for parameter #" + i + " with JdbcType " + jdbcType + " . "
                      + "Try setting a different JdbcType for this parameter or a different jdbcTypeForNull configuration property. "
                      + "Cause: " + e, e);
            }
        } else {
            try {
                setNonNullParameter(ps, i, parameter, jdbcType);
            } catch (Exception e) {
              throw new TypeException("Error setting non null for parameter #" + i + " with JdbcType " + jdbcType + " . "
                  + "Try setting a different JdbcType for this parameter or a different configuration property. " + "Cause: "
                  + e, e);
            }
        }
    }

    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, String parameter, JdbcType jdbcType) throws SQLException {
        ps.setString(i, parameter);
    }

View on GitHub (pinned to d6d39ce1c6)

Solutions

Change jdbcTypeForNull to a widely supported type such as VARCHAR in the MyBatis configuration.
Adjust the jdbcType attribute in the mapper mapping to a type the driver accepts for setNull.
Check the cause SQLException for the column constraint (NOT NULL violation means the value must be non-null).
Update the JDBC driver to a version that handles the configured null JdbcType.

Example fix

// before
configuration.setJdbcTypeForNullType(JdbcType.NULL);
// after
configuration.setJdbcTypeForNullType(JdbcType.VARCHAR);

Defensive patterns

Strategy: try-catch

Validate before calling

if (value == null) { /* ensure jdbcType is driver-supported: prefer VARCHAR, avoid NULL/OTHER */ }

Try / catch

catch (TypeException e) { if (e.getMessage().startsWith("Error setting null")) { log.error("setNull failed for param", e.getCause()); /* switch jdbcTypeForNull */ } throw e; }

Prevention

Use jdbcTypeForNull=VARCHAR, not NULL/OTHER, on restrictive drivers.
Check the driver docs for supported null JdbcTypes.
Inspect cause SQLException to distinguish constraint vs. driver issues.

When it happens

Trigger: Binding null to parameter #i throws SQLException inside setNull(i, TYPE_CODE) or setNull(i, Types.NULL): driver doesn't support Types.NULL, column type incompatible with the configured JdbcType, or driver-specific limitations (e.g. some Oracle/driver combos with certain types).

Common situations: jdbcTypeForNull set to NULL/OTHER on drivers that reject it; custom mappings specifying an exotic jdbcType (e.g. NVARCHAR) unsupported by the driver for setNull; non-null expectation on a NOT NULL column surfaces as SQL error surfaced through this path.

Understand the failure class

Background: "query failed", "%w: SQL error" — wrapped database query errors in Go libraries explained — this error's family across 3 libraries.

Related errors

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/3342826bb7d64840. Report an issue: GitHub.