From 4dd43425616a4c796059081a050dcba8aca41ba8 Mon Sep 17 00:00:00 2001
From: Bomin Zhang <bmzhang@taosdata.com>
Date: Fri, 14 Aug 2020 13:26:41 +0800
Subject: [PATCH] fix td-1142

---
 src/client/src/tscPrepare.c | 12 +++++++-----
 tests/examples/c/makefile   | 24 +++++++++++++-----------
 tests/examples/c/prepare.c  | 10 +++++++---
 3 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/src/client/src/tscPrepare.c b/src/client/src/tscPrepare.c
index 0df1c7ddc5..b996dd958a 100644
--- a/src/client/src/tscPrepare.c
+++ b/src/client/src/tscPrepare.c
@@ -613,11 +613,13 @@ int taos_stmt_execute(TAOS_STMT* stmt) {
     if (sql == NULL) {
       ret = TSDB_CODE_TSC_OUT_OF_MEMORY;
     } else {
-      taosTFree(pStmt->pSql->sqlstr);
-      pStmt->pSql->sqlstr = sql;
-      SSqlObj* pSql = taos_query((TAOS*)pStmt->taos, pStmt->pSql->sqlstr);
-      ret = taos_errno(pSql);
-      taos_free_result(pSql);
+      if (pStmt->pSql != NULL) {
+        taos_free_result(pStmt->pSql);
+        pStmt->pSql = NULL;
+      }
+      pStmt->pSql = taos_query((TAOS*)pStmt->taos, sql);
+      ret = taos_errno(pStmt->pSql);
+      free(sql);
     }
   }
   return ret;
diff --git a/tests/examples/c/makefile b/tests/examples/c/makefile
index f9653c9c96..7293a22c11 100644
--- a/tests/examples/c/makefile
+++ b/tests/examples/c/makefile
@@ -4,22 +4,24 @@
 ROOT=./
 TARGET=exe
 LFLAGS = '-Wl,-rpath,/usr/local/taos/driver/' -ltaos -lpthread -lm -lrt
-CFLAGS = -O3 -g -Wall -Wno-deprecated -fPIC -Wno-unused-result -Wconversion -Wno-char-subscripts -D_REENTRANT -Wno-format -D_REENTRANT -DLINUX -msse4.2 -Wno-unused-function -D_M_X64 \
-	-I/usr/local/taos/include -std=gnu99
+CFLAGS = -O3 -g -Wall -Wno-deprecated -fPIC -Wno-unused-result -Wconversion \
+	-Wno-char-subscripts -D_REENTRANT -Wno-format -D_REENTRANT -DLINUX \
+	-msse4.2 -Wno-unused-function -D_M_X64 -I/usr/local/taos/include -std=gnu99
 
 all: $(TARGET)
 
 exe:
-	gcc $(CFLAGS) ./asyncdemo.c -o $(ROOT)/asyncdemo $(LFLAGS)
-	gcc $(CFLAGS) ./demo.c -o $(ROOT)/demo $(LFLAGS)
-	gcc $(CFLAGS) ./prepare.c -o $(ROOT)/prepare $(LFLAGS)
-	gcc $(CFLAGS) ./stream.c -o $(ROOT)/stream $(LFLAGS)
+	gcc $(CFLAGS) ./asyncdemo.c -o $(ROOT)asyncdemo $(LFLAGS)
+	gcc $(CFLAGS) ./demo.c -o $(ROOT)demo $(LFLAGS)
+	gcc $(CFLAGS) ./prepare.c -o $(ROOT)prepare $(LFLAGS)
+	gcc $(CFLAGS) ./stream.c -o $(ROOT)stream $(LFLAGS)
 	gcc $(CFLAGS) ./subscribe.c -o $(ROOT)subscribe $(LFLAGS)
 	gcc $(CFLAGS) ./apitest.c -o $(ROOT)apitest $(LFLAGS)
 
 clean:
-	rm $(ROOT)/asyncdemo
-	rm $(ROOT)/demo
-	rm $(ROOT)/prepare
-	rm $(ROOT)/stream
-	rm $(ROOT)/subscribe
+	rm $(ROOT)asyncdemo
+	rm $(ROOT)demo
+	rm $(ROOT)prepare
+	rm $(ROOT)stream
+	rm $(ROOT)subscribe
+	rm $(ROOT)apitest
diff --git a/tests/examples/c/prepare.c b/tests/examples/c/prepare.c
index ca0942035a..7a70b744ee 100644
--- a/tests/examples/c/prepare.c
+++ b/tests/examples/c/prepare.c
@@ -195,11 +195,15 @@ int main(int argc, char *argv[])
     taos_print_row(temp, row, fields, num_fields);
     printf("%s\n", temp);
   }
+  if (rows == 2) {
+    printf("two rows are fetched as expectation\n");
+  } else {
+    printf("expect two rows, but %d rows are fetched\n", rows);
+  }
 
   taos_free_result(result);
   taos_stmt_close(stmt);
-  
-  printf("Data has been written, Please press enter to return");
-  return getchar();
+
+  return 0;
 }