jdbc.rb in logstash-input-jdbc-4.2.0

- old
+ new

@@ -60,11 +60,11 @@
 # table that match a specific artist. The following examples demonstrates a possible
 # Logstash configuration for this. The `schedule` option in this example will
 # instruct the plugin to execute this input statement on the minute, every minute.
 #
 # [source,ruby]
-# ----------------------------------
+# ------------------------------------------------------------------------------
 # input {
 #   jdbc {
 #     jdbc_driver_library => "mysql-connector-java-5.1.36-bin.jar"
 #     jdbc_driver_class => "com.mysql.jdbc.Driver"
 #     jdbc_connection_string => "jdbc:mysql://localhost:3306/mydb"
@@ -72,20 +72,35 @@
 #     parameters => { "favorite_artist" => "Beethoven" }
 #     schedule => "* * * * *"
 #     statement => "SELECT * from songs where artist = :favorite_artist"
 #   }
 # }
-# ----------------------------------
+# ------------------------------------------------------------------------------
 #
 # ==== Configuring SQL statement
 #
 # A sql statement is required for this input. This can be passed-in via a
 # statement option in the form of a string, or read from a file (`statement_filepath`). File
 # option is typically used when the SQL statement is large or cumbersome to supply in the config.
 # The file option only supports one SQL statement. The plugin will only accept one of the options.
 # It cannot read a statement from a file as well as from the `statement` configuration parameter.
 #
+# ==== Configuring multiple SQL statements 
+#
+# Configuring multiple SQL statements is useful when there is a need to query and ingest data 
+# from different database tables or views. It is possible to define separate Logstash 
+# configuration files for each statement or to define multiple statements in a single configuration 
+# file. When using multiple statements in a single Logstash configuration file, each statement 
+# has to be defined as a separate jdbc input (including jdbc driver, connection string and other 
+# required parameters). 
+#
+# Please note that if any of the statements use the `sql_last_value` parameter (e.g. for 
+# ingesting only data changed since last run), each input should define its own 
+# `last_run_metadata_path` parameter. Failure to do so will result in undesired behaviour, as
+# all inputs will store their state to the same (default) metadata file, effectively 
+# overwriting each other's `sql_last_value`.
+#
 # ==== Predefined Parameters
 #
 # Some parameters are built-in and can be used from within your queries.
 # Here is the list:
 #
@@ -95,20 +110,20 @@
 # `tracking_column` is set. It is updated accordingly after subsequent queries are run.
 # |==========================================================
 #
 # Example:
 # [source,ruby]
-# ----------------------------------
+# ---------------------------------------------------------------------------------------------------
 # input {
 #   jdbc {
 #     statement => "SELECT id, mycolumn1, mycolumn2 FROM my_table WHERE id > :sql_last_value"
 #     use_column_value => true
-#     tracking_column => id
+#     tracking_column => "id"
 #     # ... other configuration bits
 #   }
 # }
-# ----------------------------------
+# ---------------------------------------------------------------------------------------------------
 #
 class LogStash::Inputs::Jdbc < LogStash::Inputs::Base
   include LogStash::PluginMixins::Jdbc
   config_name "jdbc"
 
@@ -119,13 +134,13 @@
   #
   # To use parameters, use named parameter syntax.
   # For example:
   #
   # [source, ruby]
-  # ----------------------------------
+  # -----------------------------------------------
   # "SELECT * FROM MYTABLE WHERE id = :target_id"
-  # ----------------------------------
+  # -----------------------------------------------
   #
   # here, ":target_id" is a named parameter. You can configure named parameters
   # with the `parameters` setting.
   config :statement, :validate => :string
 
@@ -170,17 +185,18 @@
   # The character encoding for specific columns. This option will override the `:charset` option 
   # for the specified columns.
   #
   # Example:
   # [source,ruby]
-  # ----------------------------------
+  # -------------------------------------------------------
   # input {
   #   jdbc {
   #     ...
   #     columns_charset => { "column0" => "ISO-8859-1" }
   #     ...
   #   }
   # }
+  # -------------------------------------------------------
   # this will only convert column0 that has ISO-8859-1 as an original encoding.
   config :columns_charset, :validate => :hash, :default => {}
 
   public
 