renamed liteDb

Author: veiled-coder

liteDb/ReadMe.md

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+* LiteDB - A Ruby-based Lightweight Database Management System *
+LiteDB is a simple yet powerful database management system (DBMS) written in Ruby. It's designed to handle SQL queries for database operations with both case-insensitive and case-sensitive support. This lightweight DBMS uses CSV files as its storage backend, making it easy to work with and perfect for small to medium-sized projects.
+
+Features
+SQL Query Support: LiteDB supports essential SQL query commands like SELECT, INSERT, UPDATE, and DELETE.
+Case Insensitivity: You can use SQL queries in either uppercase or lowercase letters, making it user-friendly and flexible.
+CSV-Based Storage: LiteDB stores data in CSV files, making it easy to work with and suitable for small-scale projects.
+Powerful Query Engine: Utilizes regular expressions, hash manipulation, loops, block arguments, and merge sort algorithms for efficient query processing.
+Installation
+LiteDB requires Ruby to be installed on your system. You can install it using the following steps:
+
+Clone this repository to your local machine:
+
+bash
+Copy code
+git clone https://github.com/yourusername/LiteDB.git
+cd LiteDB
+Install the required gems:
+
+bash
+Copy code
+bundle install
+Usage
+You can interact with LiteDB through the command-line interface (CLI). Here are some sample SQL queries:
+
+SELECT
+ruby
+Copy code
+SELECT name,email FROM nba_player_data WHERE name='Matt Zunic'
+INSERT
+ruby
+Copy code
+INSERT INTO nba_player_data (name, year_start, year_end, position, height, weight, college) VALUES ('Alaa Abdelnaby34', 1991, 1995, 'F-C', '6-10', 240, 'Duke University')
+UPDATE
+ruby
+Copy code
+UPDATE nba_player_data SET name = 'Bill Renamed', year_start = '2330' WHERE name = 'Bill Zopf', year_start = '1971'
+DELETE
+
+DELETE FROM nba_player_data WHERE name = 'John'

liteDb/my_sqlite_cli.rb

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+require_relative 'my_sqlite_request'
+
+class MySQLite
+    def initialize
+    puts "MySQLite version 0.1 #{Time.now.strftime('%Y-%m-%d')}"
+    queryUserInput
+    end
+end    
+
+def queryUserInput
+loop do
+    print 'my_sqlite_cli>'
+    query=gets.chomp
+    result=''
+case query
+
+when 'quit'
+    puts 'exiting sqlte cli'
+    break
+when /^(\s*(SELECT|select)\s+([\w\s*,]+)\s+(FROM|from)\s+(\S+)\s*(?:(JOIN|join)\s+(\S+)\s+(on|ON)\s+(\S+))?(?:(WHERE|where)\s+(.*?))?\s*)$/
+    column_name=$3
+    table_name="#{$5}.csv"
+    where_conditions=$11
+    table_name2="#{$7}.csv"
+    join_on=$9 
+
+    result=runSelectQuery(table_name,column_name).run
+    if join_on
+        result=runJoinQuery(join_on,table_name,table_name2,column_name).run
+    end
+    if where_conditions
+        result=runSelectWhereQuery(where_conditions,table_name,column_name).run      
+    end
+
+when /^(?:INSERT|insert)\s+(?:INTO|into)\s+(\w+)(?:\s+\(([^)]+)\))?\s+(?:VALUES|values)\s+\(([^)]+)\)\s*;?\s*$/
+
+     table_name="#{$1}.csv"
+     table_column=$2
+     table_data=$3
+     hash_data_array=[]
+     parsed_table_data = CSV.parse(table_data).first
+     runInsertQuery(table_name,table_column,hash_data_array,parsed_table_data).run
+
+when /(?:UPDATE|update)\s+(\w+)\s+(?:SET|set)\s+(.+?)\s+(?:WHERE|where)\s+(.+)/
+
+    table_name="#{$1}.csv"
+    values=$2
+    where_conditions=$3
+    request=runUpdateQuery(table_name,values,where_conditions).run
+   
+when /^\s*(DELETE|delete)\s+(FROM|from)\s+(\w+)\s+(where|WHERE)\s+(.+)/
+
+    table_name="#{$3}.csv"
+     where_conditions=$5
+     request=runDeleteQuery(table_name,where_conditions,request).run
+
+
+else
+    puts 'Invalid query format. Please enter a valid query...e.g..SELECT * FROM database.csv'  
+end#when
+puts result.inspect
+# return result
+end#loop
+end#defQuery
+
+# #HELPER FUNCTIONS
+
+    
+
+def runSelectQuery(table_name,column_name)
+    request = MySqliteRequest.new
+    request = request.from(table_name)
+    if column_name=="*"
+        request = request.select(column_name)
+    else
+        columNameArray=column_name.split(",")  
+        request = request.select(*columNameArray)
+    end
+    return request
+end
+
+def runSelectWhereQuery(conditions,table_name,column_name)
+    request=runSelectQuery(table_name,column_name)
+    splitted_conditions=conditions.split(",") 
+    
+    splitted_conditions.each do |current_condition|
+        current_pair_array=current_condition.split("=")
+
+        condition_array=current_pair_array.map do |condition|
+            condition.delete_prefix("'").delete_suffix("'")
+        end
+        request=request.where(*condition_array)
+    end
+    return request
+end
+
+def runJoinQuery(join_conditions,table_name,table_name2,column_name)
+    join_conditions_array=join_conditions.split("=")
+    request=runSelectQuery(table_name,column_name)
+    request=request.join(join_conditions_array[0],table_name2,join_conditions_array[1])
+    return request
+end
+
+def runInsertQuery(table_name,table_column,hash_data_array,parsed_table_data)
+if table_column
+        split_column=table_column.split(",")
+        split_column.each_with_index do |column,i|
+        data_hash={}
+        data_hash[column] = parsed_table_data[i]
+        hash_data_array<<data_hash
+        end
+        
+ end
+
+ 
+request = MySqliteRequest.new
+request = request.insert(table_name)
+    if table_column
+        request = request.values(*hash_data_array)
+        else
+        request = request.values(*split_data)
+    end
+request
+end
+def runUpdateQuery(table_name,values,where_conditions)
+    splitted_values=values.split(", ")
+    values_to_update={}
+   
+    splitted_values.each do |value_pair|
+        value_pair_hash={}
+        #create an hash for eaac pair,then push to an array
+        value_pair_array=value_pair.split("=")
+        edited_pair_array=value_pair_array.map do |element|
+            element.strip
+        end
+     
+        value_pair_hash[edited_pair_array[0]]=edited_pair_array[1]
+        values_to_update.merge!(value_pair_hash)
+    end
+   
+
+request = MySqliteRequest.new
+request = request.update(table_name)
+request = request.values(values_to_update)
+request = processWhereConditions(where_conditions,request)
+request
+end
+
+def runDeleteQuery(table_name,where_conditions,request)
+request = MySqliteRequest.new
+request = request.delete
+request =request.from(table_name)
+request = processWhereConditions(where_conditions,request)
+request
+end
+
+def processWhereConditions(conditions,request)
+    splitted_conditions=conditions.split(",")
+
+    splitted_conditions.each do |current_condition|
+        current_pair_array=current_condition.split("=")
+        edited_pair_array=current_pair_array.map do |element|
+            element.strip
+     end
+        request=request.where(*edited_pair_array)
+    end
+    return request
+end
+MySQLite.new
+#DELETE FROM  nba_player_data WHERE name = 'John'
+
+# UPDATE nba_player_data SET name = 'Bill Renamed', year_start = '2330' WHERE name = 'Bill Zopf',year_start='1971'
+
+
+# INSERT INTO nba_player_data (name,year_start,year_end,position,height,weight,college) VALUES (Alaa Abdelnaby34,1991,1995,F-C,6-10,240,Duke University)
+# INSERT INTO nba_player_data VALUES (Alaa Abdelnaby34,1991,1995,F-C,6-10,240,"June 24, 1968",Duke University)
+
+
+
+#SELECT name,email FROM  nba_player_data WHERE name='Matt Zunic'
+