add show command for system db

source/libs/command/src/command.c

@@ -286,21 +286,25 @@ static void setCreateDBResultIntoDataBlock(SSDataBlock* pBlock, char* dbName, ch
     hashPrefix = pCfg->hashPrefix + dbFNameLen + 1;
   }
 
-  len += sprintf(
-      buf2 + VARSTR_HEADER_SIZE,
-      "CREATE DATABASE `%s` BUFFER %d CACHESIZE %d CACHEMODEL '%s' COMP %d DURATION %dm "
-      "WAL_FSYNC_PERIOD %d MAXROWS %d MINROWS %d STT_TRIGGER %d KEEP %dm,%dm,%dm PAGES %d PAGESIZE %d PRECISION '%s' REPLICA %d "
-      "WAL_LEVEL %d VGROUPS %d SINGLE_STABLE %d TABLE_PREFIX %d TABLE_SUFFIX %d TSDB_PAGESIZE %d "
-      "WAL_RETENTION_PERIOD %d WAL_RETENTION_SIZE %" PRId64 " WAL_ROLL_PERIOD %d WAL_SEGMENT_SIZE %" PRId64,
-      dbName, pCfg->buffer, pCfg->cacheSize, cacheModelStr(pCfg->cacheLast), pCfg->compression, pCfg->daysPerFile,
-      pCfg->walFsyncPeriod, pCfg->maxRows, pCfg->minRows,  pCfg->sstTrigger, pCfg->daysToKeep0, pCfg->daysToKeep1, pCfg->daysToKeep2,
-      pCfg->pages, pCfg->pageSize, prec, pCfg->replications, pCfg->walLevel, pCfg->numOfVgroups,
-      1 == pCfg->numOfStables, hashPrefix, pCfg->hashSuffix, pCfg->tsdbPageSize, pCfg->walRetentionPeriod,
-      pCfg->walRetentionSize, pCfg->walRollPeriod, pCfg->walSegmentSize);
-
-  if (retentions) {
-    len += sprintf(buf2 + VARSTR_HEADER_SIZE + len, " RETENTIONS %s", retentions);
-    taosMemoryFree(retentions);
+  if (IS_SYS_DBNAME(dbName)) {
+    len += sprintf(buf2 + VARSTR_HEADER_SIZE, "CREATE DATABASE `%s` ", dbName);
+  } else {
+    len += sprintf(
+        buf2 + VARSTR_HEADER_SIZE,
+        "CREATE DATABASE `%s` BUFFER %d CACHESIZE %d CACHEMODEL '%s' COMP %d DURATION %dm "
+        "WAL_FSYNC_PERIOD %d MAXROWS %d MINROWS %d STT_TRIGGER %d KEEP %dm,%dm,%dm PAGES %d PAGESIZE %d PRECISION '%s' REPLICA %d "
+        "WAL_LEVEL %d VGROUPS %d SINGLE_STABLE %d TABLE_PREFIX %d TABLE_SUFFIX %d TSDB_PAGESIZE %d "
+        "WAL_RETENTION_PERIOD %d WAL_RETENTION_SIZE %" PRId64 " WAL_ROLL_PERIOD %d WAL_SEGMENT_SIZE %" PRId64,
+        dbName, pCfg->buffer, pCfg->cacheSize, cacheModelStr(pCfg->cacheLast), pCfg->compression, pCfg->daysPerFile,
+        pCfg->walFsyncPeriod, pCfg->maxRows, pCfg->minRows,  pCfg->sstTrigger, pCfg->daysToKeep0, pCfg->daysToKeep1, pCfg->daysToKeep2,
+        pCfg->pages, pCfg->pageSize, prec, pCfg->replications, pCfg->walLevel, pCfg->numOfVgroups,
+        1 == pCfg->numOfStables, hashPrefix, pCfg->hashSuffix, pCfg->tsdbPageSize, pCfg->walRetentionPeriod,
+        pCfg->walRetentionSize, pCfg->walRollPeriod, pCfg->walSegmentSize);
+
+    if (retentions) {
+      len += sprintf(buf2 + VARSTR_HEADER_SIZE + len, " RETENTIONS %s", retentions);
+      taosMemoryFree(retentions);
+    }
   }
 
   (varDataLen(buf2)) = len;

source/libs/parser/src/parTranslater.c

@@ -509,6 +509,10 @@ static int32_t getDBVgVersion(STranslateContext* pCxt, const char* pDbFName, int
 }
 
 static int32_t getDBCfg(STranslateContext* pCxt, const char* pDbName, SDbCfgInfo* pInfo) {
+  if (IS_SYS_DBNAME(pDbName)) {
+    return TSDB_CODE_SUCCESS;
+  }
+
   SParseContext* pParCxt = pCxt->pParseCxt;
   SName          name;
   tNameSetDbName(&name, pCxt->pParseCxt->acctId, pDbName, strlen(pDbName));