====== How to write SQL Queries to explore database ======

Once you are opened an [[how to:opensession|MSI session]], you can explore the database by creating SQL queries. Information on MSI database and its model is available [[http://biodev.extra.cea.fr/docs/irma/doku.php?id=msidb| here ]].

===== View data from a table =====
It is possible to view data from a table like this:\\
  * In the ''Services'' Window, select a database connection
  * Expand the schema node of your choice, then the ''TABLES'' node
  * Select a table, right-click and choose ''View data'' to display table values

{{:sql_comment.png|}}

===== Create your own SQL query =====
To create a new SQL file from an hEIDI project, select the ''File > New File'' menu, then choose ''SQL File'' under the ''Other'' Category.\\
Specify a name and a project folder then ''Finish''. An empty SQL file appears on the screen. \\
Select your database in the droplist at the top.\\
{{:how_to:sqlquery_choosedb.png|}}

When you query is written, you can execute it using the ''Run SQL'' icon:

{{:how_to:sqlquery_execute1.png|}}

If you have several queries in your file, you can select one to execute, then right-click on it and choose ''Run Selection'':

{{:how_to:sqlquery_execute2.png|}}

If your query executed successfully, the result will display in a table.\\
If needed, see [[how_to:exportsqlresult|how to export an SQL result to a file]].