Update README.md

Author: sudheer

README.md

@@ -1,3 +1,30 @@
 # SQL-Engine
 
   - ***Mini-SQL*** engine in ***Python*** which will run a subset of SQL Queries using command line interface.
+  - ## **Dataset**
+    - all elements in the fields would be ***integers*** only
+    - file is named ***File1.csv***, the database table name would be ***File1***
+    - ***metadat.txt*** file will be given for schema of corresponding database tables
+      ```
+      <begin_table>
+      <table_name>
+      <attribute1>
+      ....
+      <attributeN>
+      <end_table>
+      ```
+  - ## **Queries**
+    - **Select** all records: ``` SELECT * FROM table_name; ```
+    - **Aggregate** functions: ***sum, average, min, max*** ``` SELECT MAX(col) FROM table_name; ```
+    - **Project** coloumns: ``` SELECT col FROM table_name; ```
+    - Project with **distinct**: ``` SELECT DISTINCT col FROM table_name; ```
+    - Select from **one or more tables**: ``` SELECT col1, col2 FROM table1, table2 WHERE col1=10 AND col2=20; ```
+    - Projection from one or more from two tables with **one join condition**: 
+    ```
+    a. SELECT * FROM table1, table2 WHERE table1.col1=table2.col2;
+    b. SELECT col1, col2 FROM table1, table2 WHERE table1.col1=table2.col2; 
+    ```
+    - Basic Error Handling is done
+  - ## **Execute**
+    - run SQL-Engine from **python file** ``` python sql_engine.py <query> ```
+    - run SQL-Engine from **bash script** ``` bash run.sh ```