Informix Error -2993: There is a circular join path specified in the form.

Cause and resolution

There is a circular join path specified in the form.

This form defines a series of three or more joins such that table A joins to table B, table B joins to table C, and table C joins to table A. The circularity might not be obvious due to the use of table-alias names. Review all the statements in the ATTRIBUTES section and any COMPOSITES statements, and draw a diagram of the join relationships. Then modify the form so that no circular joins are created.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-2993 fires when a form defines a series of three or more joins that loop back on themselves (table A joins to B, B joins to C, and C joins back to A) — per the official guidance, this circularity might not be obvious due to the use of table-alias names.

A chain of joins across ATTRIBUTES/COMPOSITES statements that loops back to its starting table, per the official guidance — the direct, only cause.
Table aliases obscuring the loop, per the official guidance — a named reason the circularity can be hard to spot.

Solutions / Resolution

Review all the statements in ATTRIBUTES and any COMPOSITES statements, per the official guidance.
Draw a diagram of the join relationships, per the official guidance.
Modify the form so that no circular joins are created, per the official guidance.

Examples

A circular join

ATTRIBUTES
  a = tableA.key, tableB.a_key;
  b = tableB.key, tableC.b_key;
  c = tableC.key, tableA.c_key;
-- -2993: A -> B -> C -> A forms a loop

Corrected

Break the loop by removing or redirecting one of the join legs — for example, joining C directly to B's already-resolved data instead of back to A.

Diagnostic Checks

Diagram the join relationships expressed across ATTRIBUTES and COMPOSITES, tracing through any table aliases, and confirm no cycle exists.

Related Errors / Related Topics

-2994 — "The form has exceeded the maximum number of joins between tables." A related join-limit error, about too many joins overall rather than the joins forming a cycle.

Three or more joins in the form loop back to their starting table — diagram the relationships and break the cycle.