trdsql: add page (#14896)

Co-authored-by: Wiktor Perskawiec <git@spageektti.cc>

pages/common/trdsql.md

@@ -0,0 +1,32 @@
+# trdsql
+
+> Execute SQL on CSV, LTSV, JSON, YAML, and TBLN files.
+> More information: <https://noborus.github.io/trdsql/>.
+
+- Convert object data from multiple JSON files to a CSV file with header (`-oh`) and double quote:
+
+`trdsql -ocsv -oh "SELECT * FROM {{path/to/file/*.json}}" | sed 's/\([^,]*\)/"&"/g' > {{path/to/file.csv}}`
+
+- Interpret JSON list as a table and put objects inside as columns (path/to/file.json: `{"list":[{"age":"26","name":"Tanaka"}]}`):
+
+`trdsql "SELECT * FROM {{path/to/file.json}}::.list`
+
+- Manipulate complex SQL query with data from multiple CSV files with first line is header (`-ih`):
+
+`trdsql -icsv -ih "SELECT {{column1,column2}} FROM {{path/to/file*.csv}} WHERE column2 != '' ORDER BY column1 GROUP BY column1"`
+
+- Merge content of 2 CSV files to one CSV file:
+
+`trdsql "SELECT {{column1,colum2}} FROM {{path/to/file1.csv}} UNION SELECT {{column1,column2}} FROM {{path/to/file2.csv}}"`
+
+- Connect to PostgreSQL database:
+
+`trdsql -driver postgres -dsn "host={{hostname}} port={{5433}} dbname={{database_name}}" "SELECT 1"`
+
+- Create table data to MySQL database from CSV file:
+
+`trdsql -driver mysql -dsn "{{username}}:{{password}}@{{hostname}}/{{database}}" -ih "CREATE TABLE {{table}} ({{column1}} int, {{colum2}} varchar(20)) AS SELECT {{column3}} AS {{column1}},{{column2}} FROM {{path/to/header_file.csv}}"`
+
+- Show data from compress log files:
+
+`trdsql -iltsv "SELECT * FROM {{path/to/access.log.gz}}"`