enh(query): diff support timestamp column type.

source/libs/function/src/builtins.c

@@ -1523,7 +1523,7 @@ static int32_t translateDiff(SFunctionNode* pFunc, char* pErrBuf, int32_t len) {
   }
 
   uint8_t colType = ((SExprNode*)nodesListGetNode(pFunc->pParameterList, 0))->resType.type;
-  if (!IS_SIGNED_NUMERIC_TYPE(colType) && !IS_FLOAT_TYPE(colType) && TSDB_DATA_TYPE_BOOL != colType) {
+  if (!IS_SIGNED_NUMERIC_TYPE(colType) && !IS_FLOAT_TYPE(colType) && TSDB_DATA_TYPE_BOOL != colType && TSDB_DATA_TYPE_TIMESTAMP != colType) {
     return invaildFuncParaTypeErrMsg(pErrBuf, len, pFunc->functionName);
   }
 
@@ -2204,8 +2204,6 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .finalizeFunc = elapsedFinalize,
     .invertFunc   = NULL,
     .combineFunc  = elapsedCombine,
-    //.pPartialFunc = "_elapsed_partial",
-    //.pMergeFunc   = "_elapsed_merge"
   },
   {
     .name = "_elapsed_partial",

source/libs/function/src/builtinsimpl.c

@@ -3170,6 +3170,8 @@ bool diffFunctionSetup(SqlFunctionCtx* pCtx, SResultRowEntryInfo* pResInfo) {
 static void doSetPrevVal(SDiffInfo* pDiffInfo, int32_t type, const char* pv) {
   switch (type) {
     case TSDB_DATA_TYPE_BOOL:
+      pDiffInfo->prev.i64 = *(bool*)pv? 1:0;
+      break;
     case TSDB_DATA_TYPE_TINYINT:
       pDiffInfo->prev.i64 = *(int8_t*)pv;
       break;
@@ -3179,6 +3181,7 @@ static void doSetPrevVal(SDiffInfo* pDiffInfo, int32_t type, const char* pv) {
     case TSDB_DATA_TYPE_SMALLINT:
       pDiffInfo->prev.i64 = *(int16_t*)pv;
       break;
+    case TSDB_DATA_TYPE_TIMESTAMP:
     case TSDB_DATA_TYPE_BIGINT:
       pDiffInfo->prev.i64 = *(int64_t*)pv;
       break;
@@ -3232,6 +3235,7 @@ static void doHandleDiff(SDiffInfo* pDiffInfo, int32_t type, const char* pv, SCo
       pDiffInfo->prev.i64 = v;
       break;
     }
+    case TSDB_DATA_TYPE_TIMESTAMP:
     case TSDB_DATA_TYPE_BIGINT: {
       int64_t v = *(int64_t*)pv;
       int64_t delta = factor * (v - pDiffInfo->prev.i64);  // direct previous may be null