Method to use privacy protection query language PQL to improve the security of shared date

A method to use privacy protection query language (PQL) to improve the security of shared data, comprising the following steps:

• Step 1:
• a user inputs a PQL statement according to predetermined semantic and syntactic rules and sends the PQL statement to a parsing module, wherein the PQL statement comprises:
• a PROTECT clause, a PICK clause, a WITH clause, a WITHRANGE clause, a GLOBAL clause, and a WHERE clause, wherein the parsing module comprises a lexical analyzer and a syntactic analyzer, wherein the PQL statement is checked for errors through the lexical analyzer, and correct results are sent to the syntactic analyzer, otherwise, incorrect contents are pointed out;
• Step 2:
• the syntactic analyzer performs grammatical and semantic checks on the PQL statement, generates a mapping table and a parameter table with correct results of the grammatical and semantic checks, and sends the mapping table and the parameter table to a query module and a noise-injection module respectively, otherwise, incorrect contents are pointed out;
• and
• Step 3:
• after receiving the mapping table, the query module encapsulates the mapping table into a SQL statement, said SQL statement is connected to a database for query, and final query results are sent to the noise-injection module.