Practical Analysis Strategies for SQL Questions

• First get the sql question, and then disassemble it according to the following strategy

• (1) Split the table and match the fields with the processing answers required by the question.
• (2) Confirm the requirements for processing the answer. At this time, list the functions that need to be used. The commonly used functions are count(), coalesce()sum()greastest()position()round()month_between()trunc(,' MM'),TRUNC(,'Q'),TRUNC(,'DD'),row_number()over(partition by order by )
• (3) Confirm the association scheme of the table and confirm whether the data is duplicated and deduplicated.
• (4) Determine the conditions for the main schedule and the appendix
• (5) Splice the integrated main schedule statements together
• (6) If there is no problem after running, consider time optimization (whether statement optimization is indexing, server optimization, hardware optimization)
• (7) If an error is reported after submission, first read the error message, integrate the error code, and organize the data and statements of the source of the error.