Class: Database

Inherits:
Object
  • Object
show all
Defined in:
lib/cetusql/cli_sqlite.rb

Defined Under Namespace

Classes: ResultSet

Instance Method Summary collapse

Constructor Details

#initialize(name) ⇒ Database

Returns a new instance of Database.

Raises:

  • (ArgumentError) 


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# File 'lib/cetusql/cli_sqlite.rb', line 216

def initialize(name)
  raise ArgumentError, "Database name cannot be nil" unless name
  @name = name
  connect name
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/cetusql/cli_sqlite.rb', line 281

def close
  @db = nil
  @tables = nil
end

#columns(table) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/cetusql/cli_sqlite.rb', line 232

def columns table
  raise ArgumentError, "#{$0}: table name cannot be nil" unless table
  columns, ignore = self.get_metadata table
  return columns
end

#connect(name) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/cetusql/cli_sqlite.rb', line 221

def connect name
  raise ArgumentError, "Database name cannot be nil" unless name
  @tables = nil
  @db = SQLite3::Database.new(name) 
end

#execute_query(sql) ⇒ Object 



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# File 'lib/cetusql/cli_sqlite.rb', line 270

def execute_query sql
  columns, *rows = @db.execute2(sql)
  content = rows
  return nil if content.nil? or content[0].nil?
  datatypes = content[0].types 
  rs = ResultSet.new(content, columns, datatypes)
  return rs
end

#get_data(sql) ⇒ Object Also known as: sql

runs sql query and returns an array of arrays



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# File 'lib/cetusql/cli_sqlite.rb', line 262

def get_data sql
  #$log.debug "SQL: #{sql} "
  columns, *rows = @db.execute2(sql)
  #$log.debug "XXX COLUMNS #{sql}, #{rows.count}  "
  content = rows
  return content
end

#get_metadata(table) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/cetusql/cli_sqlite.rb', line 252

def get_metadata table
  raise ArgumentError, "#{$0}: table name cannot be nil" unless table
  sql =  "select * from #{table} limit 1"
  columns, *rows = @db.execute2(sql)
  content = rows
  return nil if content.nil? or content[0].nil?
  datatypes = content[0].types 
  return columns, datatypes
end

#indexed_columns(table) ⇒ Object 



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# File 'lib/cetusql/cli_sqlite.rb', line 237

def indexed_columns table
  indexes = sql %Q{select sql from sqlite_master where type='index' and tbl_name = "#{table}" }
  return nil if indexes == []
  #pp indexes
  arr = []
  indexes.each do |ind|
    if ind.first.nil?
      arr << "auto?"
      next
    end
    m = ind.first.match /\((.*)\)/
    arr << m[1] if m
  end
  return arr.join(",")
end

#sql_recent_rows(tablename) ⇒ Object 



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# File 'lib/cetusql/cli_sqlite.rb', line 278

def sql_recent_rows tablename
  sql =  "SELECT * from #{tablename} ORDER by rowid DESC LIMIT 100"
end

#tables ⇒ Object 



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# File 'lib/cetusql/cli_sqlite.rb', line 226

def tables
  return @tables if @tables
  tables = sql "SELECT name FROM sqlite_master WHERE type='table' ORDER BY name"
  tables.collect!{|x| x[0] }  ## 1.9 hack, but will it run on 1.8 ??
  @tables = tables
end