diff options
Diffstat (limited to 'src/vdbe.c')
| -rw-r--r-- | src/vdbe.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/src/vdbe.c b/src/vdbe.c index 4d643d726..b00174bb1 100644 --- a/src/vdbe.c +++ b/src/vdbe.c @@ -6693,12 +6693,18 @@ case OP_VFilter: { /* jump */ #endif /* SQLITE_OMIT_VIRTUALTABLE */ #ifndef SQLITE_OMIT_VIRTUALTABLE -/* Opcode: VColumn P1 P2 P3 * * +/* Opcode: VColumn P1 P2 P3 P4 * ** Synopsis: r[P3]=vcolumn(P2) ** -** Store the value of the P2-th column of -** the row of the virtual-table that the -** P1 cursor is pointing to into register P3. +** Store in register P3 the value of the P2-th column of +** the current row of the virtual-table of cursor P1. +** +** If the VColumn opcode is being used to fetch the value of +** an unchanging column during an UPDATE operation, then the P4 +** value is 1. Otherwise, P4 is 0. The P4 value is returned +** by sqlite3_vtab_nochange() routine can can be used +** by virtual table implementations to return special "no-change" +** marks which can be more efficient, depending on the virtual table. */ case OP_VColumn: { sqlite3_vtab *pVtab; @@ -6720,6 +6726,7 @@ case OP_VColumn: { assert( pModule->xColumn ); memset(&sContext, 0, sizeof(sContext)); sContext.pOut = pDest; + sContext.bVtabNoChng = pOp->p4.i!=0; MemSetTypeFlag(pDest, MEM_Null); rc = pModule->xColumn(pCur->uc.pVCur, &sContext, pOp->p2); sqlite3VtabImportErrmsg(p, pVtab); |