diff --git a/_FiveSql2/src/TSqlExecutor.prg b/_FiveSql2/src/TSqlExecutor.prg
index 1f0b7d8..2e75f46 100644
--- a/_FiveSql2/src/TSqlExecutor.prg
+++ b/_FiveSql2/src/TSqlExecutor.prg
@@ -2400,9 +2400,6 @@ METHOD RunInsert() CLASS TSqlExecutor
 
    nWA := SqlExecOpenTable( cTable, cAlias )
 
-   /* Transaction logging */
-   ::oTxn:LogRecord( cAlias, RecNo(), "INSERT" )
-
    dbAppend()
    IF Len( aFields ) > 0
       FOR i := 1 TO Min( Len( aFields ), Len( aValExprs ) )
@@ -2459,6 +2456,12 @@ METHOD RunInsert() CLASS TSqlExecutor
       NEXT
    ENDIF
 
+   /* Transaction logging — after validation passes, so a rolled-back
+    * CHECK/FK failure doesn't leave a spurious INSERT in the log at
+    * the old record's position. LogRecord must also see the new
+    * RecNo, which only exists post-dbAppend. */
+   ::oTxn:LogRecord( cAlias, RecNo(), "INSERT" )
+
    /* Commit per INSERT when the WA cache is off (legacy durability
     * guarantee). With the cache on, the caller batches via an
     * explicit SqlWACacheDisable+dbCloseAll at shutdown — skipping
@@ -2477,6 +2480,8 @@ METHOD RunUpdate() CLASS TSqlExecutor
    LOCAL cTable, aSet, xWhere, cAlias, nWA, i, nFPos, xVal
    LOCAL nAffected := 0
    LOCAL aFPos, aValuePc, pcWhere, lAllOk, cValSrc
+   LOCAL aPrevVals, lValid
+   LOCAL hConstraints, lHasConstraints
 
    cTable := ::hQuery[ "table" ]
    aSet   := ::hQuery[ "set" ]
@@ -2563,19 +2568,56 @@ METHOD RunUpdate() CLASS TSqlExecutor
    ENDIF
 
    /* Fallback: PRG scan loop — handles txn logging + non-compilable
-    * expressions (subquery, complex CASE, UDF in value or WHERE). */
+    * expressions (subquery, complex CASE, UDF in value or WHERE).
+    *
+    * Validates CHECK + FK only when the table has SQL-level
+    * constraints (a `.fsc` metadata file exists). Tables created
+    * via plain dbCreate have no constraints and skip the validator
+    * entirely — avoids a recursive five_SQL call inside every
+    * UPDATE's SqlValidateCheckRecord on transaction-active paths
+    * where the re-entry would deadlock the executor state. */
+   hConstraints := SqlLoadConstraints( cTable )
+   lHasConstraints := Len( hConstraints[ "check" ] ) > 0 .OR. ;
+                      Len( hConstraints[ "fk" ] ) > 0
+
    dbGoTop()
    WHILE ! Eof()
       IF xWhere == NIL .OR. SqlIsTrue( ::EvalExpr( xWhere ) )
          IF dbRLock( RecNo() )
             ::oTxn:LogRecord( cAlias, RecNo(), "UPDATE" )
+            aPrevVals := {}
             FOR i := 1 TO Len( aSet )
                nFPos := FieldPos( aSet[ i ][ 1 ] )
                IF nFPos > 0
+                  AAdd( aPrevVals, { nFPos, FieldGet( nFPos ) } )
                   xVal := ::EvalExpr( aSet[ i ][ 2 ] )
                   FieldPut( nFPos, xVal )
                ENDIF
             NEXT
+            lValid := .T.
+            IF lHasConstraints
+               lValid := SqlValidateCheckRecord( cTable )
+               IF lValid
+                  FOR i := 1 TO Len( aSet )
+                     nFPos := FieldPos( aSet[ i ][ 1 ] )
+                     IF nFPos > 0 .AND. ;
+                        ! SqlValidateFKRecord( cTable, aSet[ i ][ 1 ], FieldGet( nFPos ) )
+                        lValid := .F.
+                        EXIT
+                     ENDIF
+                  NEXT
+               ENDIF
+            ENDIF
+            IF ! lValid
+               /* Roll back the in-memory field changes before unlocking. */
+               FOR i := 1 TO Len( aPrevVals )
+                  FieldPut( aPrevVals[ i ][ 1 ], aPrevVals[ i ][ 2 ] )
+               NEXT
+               dbRUnlock( RecNo() )
+               SqlExecCloseTable( cAlias, nWA )
+               RETURN ::MakeError( SQL_ERR_GRAMMAR, ;
+                  "UPDATE constraint violation on " + cTable )
+            ENDIF
             dbRUnlock( RecNo() )
             nAffected++
          ENDIF
@@ -2608,6 +2650,10 @@ METHOD RunDelete() CLASS TSqlExecutor
    WHILE ! Eof()
       IF xWhere == NIL .OR. SqlIsTrue( ::EvalExpr( xWhere ) )
          IF dbRLock( RecNo() )
+            /* Transaction log the deletion so BEGIN TRANSACTION /
+             * ROLLBACK can undo it — RunInsert/RunUpdate log, RunDelete
+             * used to silently skip. */
+            ::oTxn:LogRecord( cAlias, RecNo(), "DELETE" )
             dbDelete()
             dbRUnlock( RecNo() )
             nAffected++