SQLite

  Index *pIdx;         /* Pointer to one of the indices */
  Index *pPk = 0;      /* The PRIMARY KEY index */
  sqlite3 *db;         /* Database connection */
  int i;               /* loop counter */
  int ix;              /* Index loop counter */
  int nCol;            /* Number of columns */
  int onError;         /* Conflict resolution strategy */

  int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */
  int nPkField;        /* Number of fields in PRIMARY KEY. 1 for ROWID tables */
  Index *pUpIdx = 0;   /* Index to which to apply the upsert */
  u8 isUpdate;         /* True if this is an UPDATE operation */
  u8 bAffinityDone = 0;  /* True if the OP_Affinity operation has been run */
  int upsertBypass = 0;  /* Address of Goto to bypass upsert subroutine */
  int upsertJump = 0;    /* Address of Goto that jumps into upsert subroutine */

  /* Record that this module has started */
  VdbeModuleComment((v, "BEGIN: GenCnstCks(%d,%d,%d,%d,%d)",
                     iDataCur, iIdxCur, regNewData, regOldData, pkChng));

  /* Test all NOT NULL constraints.
  */
  if( pTab->tabFlags & TF_HasNotNull ){
    int b2ndPass = 0;         /* True if currently running 2nd pass */
    int nSeenReplace = 0;     /* Number of ON CONFLICT REPLACE operations */
    int nGenerated = 0;       /* Number of generated columns with NOT NULL */
    while(1){  /* Make 2 passes over columns. Exit loop via "break" */
      for(i=0; i<nCol; i++){
        int iReg;                        /* Register holding column value */
        Column *pCol = &pTab->aCol[i];   /* The column to check for NOT NULL */
        int isGenerated;                 /* non-zero if column is generated */
        onError = pCol->notNull;
        if( onError==OE_None ) continue; /* No NOT NULL on this column */
        if( i==pTab->iPKey ){
          continue;        /* ROWID is never NULL */
        }
        isGenerated = pCol->colFlags & COLFLAG_GENERATED;
        if( isGenerated && !b2ndPass ){
          nGenerated++;
          continue;        /* Generated columns processed on 2nd pass */
        }
        if( aiChng && aiChng[i]<0 && !isGenerated ){
          /* Do not check NOT NULL on columns that do not change */
          continue;
        }
        if( overrideError!=OE_Default ){
          onError = overrideError;
        }else if( onError==OE_Default ){
          onError = OE_Abort;
        }
        if( onError==OE_Replace ){
          if( b2ndPass        /* REPLACE becomes ABORT on the 2nd pass */
           || pCol->pDflt==0  /* REPLACE is ABORT if no DEFAULT value */
          ){
            testcase( pCol->colFlags & COLFLAG_VIRTUAL );
            testcase( pCol->colFlags & COLFLAG_STORED );
            testcase( pCol->colFlags & COLFLAG_GENERATED );
            onError = OE_Abort;
          }else{
            assert( !isGenerated );
          }
        }else if( b2ndPass && !isGenerated ){
          continue;
        }
        assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
            || onError==OE_Ignore || onError==OE_Replace );

        testcase( i!=sqlite3TableColumnToStorage(pTab, i) );


        iReg = sqlite3TableColumnToStorage(pTab, i) + regNewData + 1;
        switch( onError ){
          case OE_Replace: {

            int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, iReg);

            VdbeCoverage(v);
            assert( (pCol->colFlags & COLFLAG_GENERATED)==0 );
            nSeenReplace++;
            sqlite3ExprCode(pParse, pCol->pDflt, iReg);
            sqlite3VdbeJumpHere(v, addr1);





            break;
          }
          case OE_Abort:
            sqlite3MayAbort(pParse);
            /* Fall through */
          case OE_Rollback:
          case OE_Fail: {
            char *zMsg = sqlite3MPrintf(db, "%s.%s", pTab->zName,
                                        pCol->zName);
            sqlite3VdbeAddOp3(v, OP_HaltIfNull, SQLITE_CONSTRAINT_NOTNULL,
                              onError, iReg);
            sqlite3VdbeAppendP4(v, zMsg, P4_DYNAMIC);
            sqlite3VdbeChangeP5(v, P5_ConstraintNotNull);
            VdbeCoverage(v);

            break;
          }
          default: {
            assert( onError==OE_Ignore );
            sqlite3VdbeAddOp2(v, OP_IsNull, iReg, ignoreDest);
            VdbeCoverage(v);
            break;
          }
        } /* end switch(onError) */
      } /* end loop i over columns */
      if( nGenerated==0 && nSeenReplace==0 ){
        /* If there are no generated columns with NOT NULL constraints
        ** and no NOT NULL ON CONFLICT REPLACE constraints, then a single
        ** pass is sufficient */
        break;
      }
      if( b2ndPass ) break;  /* Never need more than 2 passes */
      b2ndPass = 1;
      if( nSeenReplace>0 && (pTab->tabFlags & TF_HasGenerated)!=0 ){
        /* If any NOT NULL ON CONFLICT REPLACE constraints fired on the
        ** first pass, recomputed values for all generated columns, as
        ** those values might depend on columns affected by the REPLACE.
        */
        sqlite3ComputeGeneratedColumns(pParse, regNewData+1, pTab);
      }
    } /* end of 2-pass loop */
  } /* end if( has-not-null-constraints ) */

  /* Test all CHECK constraints
  */
#ifndef SQLITE_OMIT_CHECK
  if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
    ExprList *pCheck = pTab->pCheck;
    pParse->iSelfTab = -(regNewData+1);

do_catchsql_test gencol1-6.10 {
  DROP TABLE IF EXISTS t0;
  CREATE TABLE t0(c0 NOT NULL AS(c1), c1);
  REPLACE INTO t0(c1) VALUES(NULL);
} {1 {NOT NULL constraint failed: t0.c0}}

# 2019-11-06 ticket https://www.sqlite.org/src/info/2399f5986134f79c
# 2019-12-27 ticket https://www.sqlite.org/src/info/5fbc159eeb092130
# 2019-12-27 ticket https://www.sqlite.org/src/info/37823501c68a09f9
#
# All of the above tickets deal with NOT NULL ON CONFLICT REPLACE
# constraints on tables that have generated columns.
#
reset_db
do_execsql_test gencol1-7.10 {

  CREATE TABLE t0 (c0 GENERATED ALWAYS AS (1), c1 UNIQUE, c2 UNIQUE);
  INSERT INTO t0(c1) VALUES (1);
  SELECT quote(0 = t0.c2 OR t0.c1 BETWEEN t0.c2 AND 1) FROM t0;
} {NULL}
do_execsql_test gencol1-7.11 {
  DROP TABLE t0;
  CREATE TABLE t0(c0 NOT NULL DEFAULT 'xyz', c1 AS(c0) NOT NULL);
  REPLACE INTO t0(c0) VALUES(NULL);
  SELECT * FROM t0;
} {xyz xyz}
do_execsql_test gencol1-7.12 {
  DROP TABLE t0;
  CREATE TABLE t0(c0 NOT NULL DEFAULT 'xyz', c1 AS(c0) STORED NOT NULL);
  REPLACE INTO t0(c0) VALUES(NULL);
  SELECT * FROM t0;
} {xyz xyz}
do_execsql_test gencol1-7.20 {
  CREATE TABLE t1(
   a NOT NULL DEFAULT 'aaa',
   b AS(c) NOT NULL,
   c NOT NULL DEFAULT 'ccc');
  REPLACE INTO t1(a,c) VALUES(NULL,NULL);
  SELECT * FROM t1;
} {aaa ccc ccc}
do_execsql_test gencol1-7.21 {
  DROP TABLE t1;
  CREATE TABLE t1(
   a NOT NULL DEFAULT 'aaa',
   b AS(c) STORED NOT NULL,
   c NOT NULL DEFAULT 'ccc');
  REPLACE INTO t1(a,c) VALUES(NULL,NULL);
  SELECT * FROM t1;
} {aaa ccc ccc}
do_execsql_test gencol1-7.30 {
  CREATE TABLE t2(
   a NOT NULL DEFAULT 'aaa',
   b AS(a) NOT NULL,
   c NOT NULL DEFAULT 'ccc');
  REPLACE INTO t2(a,c) VALUES(NULL,NULL);
  SELECT * FROM t2;
} {aaa aaa ccc}
do_execsql_test gencol1-7.31 {
  DROP TABLE t2;
  CREATE TABLE t2(
   a NOT NULL DEFAULT 'aaa',
   b AS(a) STORED NOT NULL,
   c NOT NULL DEFAULT 'ccc');
  REPLACE INTO t2(a,c) VALUES(NULL,NULL);
  SELECT * FROM t2;
} {aaa aaa ccc}
do_execsql_test gencol1-7.40 {
  CREATE TABLE t3(a NOT NULL DEFAULT 123, b AS(a) UNIQUE);
  REPLACE INTO t3 VALUES(NULL);
  SELECT * FROM t3;
} {123 123}
do_execsql_test gencol1-7.41 {
  SELECT * FROM t3 WHERE b=123;
} {123 123}
do_execsql_test gencol1-7.50 {
  CREATE TABLE t4(a NOT NULL DEFAULT 123, b AS(a*10+4) STORED UNIQUE);
  REPLACE INTO t4 VALUES(NULL);
  SELECT * FROM t4;
} {123 1234}
do_execsql_test gencol1-7.51 {
  SELECT * FROM t4 WHERE b=1234;
} {123 1234}

# 2019-11-06 ticket 4fc08501f4e56692
do_execsql_test gencol1-8.10 {
  DROP TABLE IF EXISTS t0;
  CREATE TABLE t0(
    c0 AS (('a', 9) < ('b', c1)),
    c1 AS (1),

    c2 AS(c1) CHECK(c2)
  );
  UPDATE t0 SET c0 = NULL;
} {1 {generated column loop on "c2"}}

# 2019-11-21 Problems in the new generated column logic
# reported by Yongheng Chen and Rui Zhong
reset_db
do_execsql_test gencol1-9.10 {
  PRAGMA foreign_keys=OFF;

  CREATE TABLE t1(aa , bb AS (17) UNIQUE);
  INSERT INTO t1 VALUES(17);
  CREATE TABLE t2(cc);
  INSERT INTO t2 VALUES(41);
  SELECT * FROM t2 JOIN t1 WHERE t1.bb=t1.aa AND t1.bb=17;
} {41 17 17}
do_execsql_test gencol1-9.20 {