add README.md

src/connector/odbc/README.md

+
+# ODBC Driver #
+
+- **very initial implementation of ODBC driver for TAOS
+
+- **currently partially supported ODBC functions are: `
+SQLAllocEnv
+SQLFreeEnv
+SQLAllocConnect
+SQLFreeConnect
+SQLConnect
+SQLDisconnect
+SQLAllocStmt
+SQLAllocHandle
+SQLFreeStmt
+SQLExecDirect
+SQLExecDirectW
+SQLNumResultCols
+SQLRowCount
+SQLColAttribute
+SQLGetData
+SQLFetch
+SQLPrepare
+SQLExecute
+SQLGetDiagField
+SQLGetDiagRec
+SQLBindParameter
+SQLDriverConnect
+SQLSetConnectAttr
+SQLDescribeCol
+SQLNumParams
+SQLSetStmtAttr
+`
+
+- **internationalized, you can specify different charset/code page for easy going. eg.: insert `utf-8.zh_cn` characters into database located in linux machine, while query them out in `gb2312/gb18030/...` code page in your chinese windows machine, or vice-versa. and much fun, insert `gb2312/gb18030/...` characters into database located in linux box from
+your japanese windows box, and query them out in your local chinese  windows machine.
+
+- **enable ODBC-aware software to communicate with TAOS.
+
+- **enable any language with ODBC-bindings/ODBC-plugings to communicate with TAOS
+
+- **still going on...
+
+# Building and Testing
+**Note**: all `work` is done in TDengine's project directory
+
+
+# Building under Linux, use Ubuntu as example
+```
+sudo apt install unixodbc unixodbc-dev flex
+rm -rf debug && cmake -B debug && cmake --build debug && cmake --install debug && echo yes
+```
+# Building under Windows, use Windows 10 as example
+- install windows `flex` port. We use [https://github.com/lexxmark/winflexbison](url) at the moment. Please be noted to append `<path_to_win_flex.exe>` to your `PATH`.
+- install Microsoft Visual Studio, take VS2015 as example here
+- `"C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" amd64`
+- `rmdir /s /q debug`
+- `cmake -G "NMake Makefiles" -B debug`
+- `cmake --build debug`
+- `cmake --install debug`
+- open your `Command Prompt` with Administrator's privilidge
+- remove previously installed TAOS ODBC driver: run `C:\TDengine\todbcinst -u -f -n TAOS`
+- install TAOS ODBC driver that was just built: run `C:\TDengine\todbcinst -i -n TAOS -p C:\TDengine\driver`
+
+# Test
+we highly suggest that you build both in linux(ubuntu) and windows(windows 10) platform, because currently TAOS only has it's server-side port on linux platform.
+**Note1**: content within <> shall be modified to match your environment
+**Note2**: `.stmts` source files are all encoded in `UTF-8`
+## start taosd in linux, suppose charset is `UTF-8` as default
+```
+taosd -c ./debug/test/cfg
+```
+## create data in linux
+```
+./debug/build/bin/tcodbc 'Driver=TAOS;UID=<uid>;PWD=<pwd>;Host=<fqdn>:6030;server_enc=UTF-8' ./src/connector/odbc/tests/create_data.stmts
+```
+## query data in windows
+```
+.\debug\build\bin\tcodbc "Driver=TAOS;UID=<uid>;PWD=<pwd>;Host=<fqdn>:6030;server_enc=UTF-8" .\src\connector\odbc\tests\query_data.stmts
+```
+
+

src/connector/odbc/tests/main.c

@@ -16,7 +16,10 @@
 do {                                              \
   D("testing: %s", #statement);                   \
   int r = (statement);                            \
-  if (r) return 1;                                \
+  if (r) {                                        \
+    D("testing failed: %s", #statement);          \
+    return 1;                                     \
+  }                                               \
 } while (0);
 
 
@@ -543,6 +546,7 @@ int main(int argc, char *argv[]) {
     CHK_TEST(test_sqls(dsn, uid, pwd, connstr, sqls));
   }
 
+  D("Done!");
   return 0;
 }
 

src/connector/odbc/tools/main.c

@@ -113,6 +113,8 @@ static int do_install(int i, int argc, char *argv[]) {
     return -1;
   }
 
+  fprintf(stderr, "ODBC driver [%s] has been installed in [%s], and UsageCount is now [%d]\n",
+          driverName, driverPath, usageCount);
   return argc;
 }
 
@@ -152,8 +154,12 @@ static int do_uninstall(int i, int argc, char *argv[]) {
       fprintf(stderr, "failed to remove driver [%s]\n", driverName);
       return -1;
     }
-    if (!forceful) return argc;
+    if (!forceful) {
+      fprintf(stderr, "UsageCount for ODBC driver [%s] is now: [%d]\n", driverName, usageCount);
+      return argc;
+    }
   } while (usageCount > 0);
+  fprintf(stderr, "ODBC driver [%s] is now fully uninstalled\n", driverName);
   return argc;
 }