To improve the error detection efficiency and the benefit of regression testing of test case sequence， a test case prioritization approach based on historical data and multi-objective optimization was proposed. Firstly， the test case set was clustered according to the text topic similarity and code coverage similarity of test cases， and the association rules were mined for execution failure relationships between test cases according to the historical execution information， thereby preparing for the subsequent process. Then， the multi-objective optimization algorithm was used to sort the test cases in each cluster. After that， the final sorting sequence was generated to separate the similar test cases. Finally， the association rules between test cases were used to dynamically adjust the execution order of test cases， so that the test cases that may fail were executed with priority， so as to further improve the efficiency of defect detection. Compared with random search approach， the approach based on clustering， the approach based on topic model， the approach based on association rules and multi-objective optimization， the proposed approach has the average value of Average Percentage of Faults Detected （APFD） increased by 12.59%， 5.98%， 3.01% and 2.95%， respectively， and has the average value of APFD cost-cognizant （APFDc） increased by 17.17%， 5.04%， 5.08% and 8.21%， respectively. Experimental results show that the proposed approach can improve the benefit of regression testing effectively.

It is important to generate test data and database state for database system testing. The algorithm of Reverse Query Processing (RQP) provides a method to generate test data for database system testing, but it can only be used to process the Select query. In order to address this limitation, RQP was expanded into RMP (Reverse Manipulate Processing) so that it can be used for all the data manipulation statement in SQL. The main idea of RMP was to transform DML statements, such as Delete, Insert, Update, into Select. That is to use Select to describe the conditions that the database instance should meet the requirement of testing DML statements. Then RQP gets the transformed Select statements as inputs and returns a possible database instance that satisfies the conditions. RMP can reversely process the fundamental SQL statements and provide better support to automatic data generation for database system test.