[TD-1389]<test>: update query null value test

[TD-1407] <fix> fix an issue coverity reports

Update administrator-ch.md

Update administrator-ch.md

Master

[TD-1331]<docs> update taos sql and add error code

Master

TD-1401

Feature/crash

[TD-1039]<fix>：query 'select database()' return  result like mysql 

Master

fix TD-1387

[TD-1370]<enhance>: support function count(1)

[TD-1309]<fix>: comparation of incompatible types should raise an error(#3349)

Update faq-ch.md

fix error

TD-1363  Ensure the sync of mnode not interrupted

[TD-1376]

[TD-1360]<test>: add test case - read binary data using Java

minor changes