adding data
Insert a single tuple
1. Use the SSMS tool to update the data in the data table
2. Use SQL to update the data in the data table
INSERT
VALUES (assign values to the attributes of the new tuple, string constants and time and date should be enclosed in single quotes)
Insert multiple tuples
Insert tuples via subquery
change the data
delete data
Use SQL to delete the data in the data table
Query data
1. Basic query (single table query)
SELECT <field name> FROM <table or view name> Query all data in the table and return all information
SELECT <attribute column to be returned 1> [,<attribute column to be returned 2>] FROM <table name or view name> Query all data in the table and return partial information
SELECT <attribute column to be returned 1> alias 1 [,<attribute column to return 2> alias 2]... FROM <table name or view name> Query all data in the table, return part of the information, change the title display
SELECT TOP N <target column expression> FROM <table name or view name> Query the top N data in the table
SELECT <target column expression> FROM <table name or view name> ORDER BY [ASC|DESC] Query the data in the table and sort it
--ASC is ascending sorting, --DESC is descending sorting (if not specified, the default ascending sorting)
2. Conditional query
3. Range condition query
4. Set condition query
5. Null value condition query
6. Logical condition query
7. Fuzzy query
8. Statistics query
9. Group query
10. Multi-table query
11. Connect query
Cross-connect query
