Netezza / PureData – How To Quote a Single Quote in Netezza SQL

How To Quote a Single Quote in Netezza SQL?

The short answer is to use four single quotes (””), which will result in a single quote within the select statement results.

How to Assemble the SQL to Quote a Single Quote in a SQL Select Statement

Knowing how to construct a list to embed in a SQL where clause ‘in’ list or to add to an ETL job can be a serious time saver eliminating the need to manually edit large lists.  In the example below, I used the Select result set to create a rather long list of values, which needed to be included in an ELT where clause.  By:

  • Adding the comma delimiter (‘,’) and a Concatenate (||) on the front
  • Followed by adding a quoted single Quote (entered as four single quotes (””)) and a Concatenate (||)
  • The Field I which to have delaminated and Quoted (S1.ORDER_NUM)
  • And closed with a quoted single Quote (entered as four single quotes (””))

This results in a delimited and quoted list ( ,’116490856′) which needs only to have the parentheses added and the first comma removed, which is much less work than manually editing the 200 item that resulted from this select.

Example SQL:

SELECT Distinct

‘,’||””|| S1.ORDER_NUM||”” as Quoted_Order_Number

FROM Sales S1

How to Quote A Single Quote Example SQL
How to Quote A Single Quote Example SQL

Related Reference

Netezza / PureData – Table Describe SQL

Netezza Puredata Table Describe SQL
Netezza / Puredata Table Describe SQL

If you want to describe a PureData / Netezza table in SQL, it can be done, but Netezza doesn’t have a describe command.  Here is a quick SQL, which will give the basic structure of a table or a view.  Honestly, if you have Aginity Generating the DDL is fast and more informative, at least to me.  If you have permissions to access NZSQL you can also use the slash commands (e.g. \d).

Example Netezza Table Describe SQL

select  name as Table_name,

owner as Table_Owner,

Createdate as Table_Created_Date,

type as Table_Type,

Database as Database_Name,

schema as Database_Schema,

attnum as Field_Order,

attname as Field_Name,

format_type as Field_Type,

attnotnull as Field_Not_Null_Indicator,

attlen as Field_Length

from _v_relation_column

where

name='<<Table Name Here>>’

Order by attnum;

 

Related References

IBM Knowledge Center, PureData System for Analytics, Version 7.2.1

IBM Netezza database user documentation, Command-line options for nzsql, Internal slash options

IBM Knowledge Center, PureData System for Analytics, Version 7.2.1

IBM Netezza getting started tips, About the Netezza data warehouse appliance, Commands and queries, Basic Netezza SQL information, Commonly used nzsql internal slash commands

IBM Knowledge Center, PureData System for Analytics, Version 7.2.1

IBM Netezza database user documentation, Netezza SQL introduction, The nzsql command options, Slash options

 

 

Netezza / PureData – Substring Function On Specific Delimiter

SQL (Structured Query Language), Netezza / PureData - Substring Function On Specific Delimiter, substr
Netezza / PureData – Substring Function On Specific Delimiter

The function Substring (SUBSTR) in Netezza PureData provides the capability parse character type fields based on position within a character string.  However, it is possible, with a little creativity, to substring based on the position of a character in the string. This approach give more flexibility to the substring function and makes the substring more useful in many cases. This approach works fine with either the substring or substr functions.  In this example, I used the position example provide the numbers for the string command.

 

Example Substring SQL

Netezza PureData Substring Function On Specific Character In String, substring, substr
Netezza PureData Substring Function On Specific Character In String

 

Substring SQL Used In Example

select LOCATIONTEXT

,position(‘,’ in LOCATIONTEXT) as Comma_Postion_In_String

—without Adjustment

,SUBSTRING(LOCATIONTEXT,position(‘,’ in LOCATIONTEXT)) as Substring_On_Comma

—Adjusted to account for extra space

,SUBSTRING(LOCATIONTEXT,position(‘,’ in LOCATIONTEXT)+2) as Substring_On_Comma_Ajusted

,’==Breaking_Up_The_Sting==’ as Divider

— breaking up the string

,SUBSTRING(LOCATIONTEXT,1, position(‘ ‘ in LOCATIONTEXT)-1) as Beggining_of_String

,SUBSTRING(LOCATIONTEXT,position(‘ ‘ in LOCATIONTEXT)+1, position(‘ ‘ in LOCATIONTEXT)-1) as Middle_Of_String

,SUBSTRING(LOCATIONTEXT,position(‘,’ in LOCATIONTEXT)+2) as End_Of_String

 

FROM Blog.D_ZIPCODE

where STATE = ‘PR’

AND CITY = ‘REPTO ROBLES’

Related References

IBM Knowledge Center, PureData System for Analytics, Version 7.2.1

IBM Netezza database user documentation, Netezza SQL basics, Netezza SQL extensions, Character string functions

IBM Knowledge Center, PureData System for Analytics, Version 7.1.0

IBM Netezza Database User’s Guide, Netezza SQL basics, Functions and operators, Functions, Standard string functions

IBM Knowledge Center, PureData System for Analytics, Version 7.2.1

IBM Netezza database user documentation, Netezza SQL command reference, Functions

Aginity for Netezza – How to Display Query Results in a Single Row Grid

Aginity
Aginity

Displaying your Netezza query results in a grid can be useful.  Especially, when desiring to navigation left and right to see an entire rows data and to avoid the distraction of other rows being displayed on the screen. I use this capability in Aginity when I’m proofing code results and/or validating data in a table.

How To switch to the Single Row Grid

  • Execute your Query
  • When the results return, right click on the gray bar above your results (where you see the drag a column box
  • Choose the ‘Show a Single Row Grid’ Menu item

    Aginity Show Single Row Grid
    Aginity Show Single Row Grid

 

Grid View Change

  • Your result display will change from a horizontal row to a vertical grid as shown below

Aginity Single Row Grid Display
Aginity Single Row Grid Display

How to Navigate in the Single Row Grid

  • To navigate in the single row grid, use the buttons provided at the bottom of the results section.

Aginity Single Row Grid Navigation Buttons
Aginity Single Row Grid Navigation Buttons

Related References

 

Netezza / PureData – How to add multiple columns to a Netezza table in one SQL

add multiple columns to a Netezza table , alter table
SQL (Structured Query Language)

 

I had this example floating around in a notepad for a while, but I find myself coming back it occasionally.  So, I thought I would add it to this blog for future reference.

The Table Alter Process

This is an outline of the Alter table process I follow, for reference, in case it is helpful.

  • Generate DDL in Aginity and make backup original table structure
  • Perform Insert into backup table from original table
  • Create Alter SQL
  • Execute Alter SQL
  • Refresh Aginity table columns
  • Generate new DDL
  • visually validate DDL Structure
  • If correct, archive copy of DDL to version control system
  • Preform any update commands, if required, required to populate the new columns.
  • Execute post alter table cleanup
    • Groom Versions
    • Groom table
    • Generate statistics
  • Once the any required processes and the data have been validated, drop the backup table.

 

Basic Alter SQL Command Structure

Here is the basic syntax for adding multiple columns:

ALTER TABLE <<OWNER>>.<<TABLENAME>>

ADD COLUMN <<FieldName1>> <<Field Type>> <<Constraint, if applicable>>

, <<FieldName2>> <<Field Type>> <<Constraint, if applicable>>;

 

Example Alter SQL Command to a Multiple Columns

Here is a quick example, which is adding four columns:

Example SQL Adding Multiple Columns

ALTER TABLE BLOG.PRODUCT_DIM

ADD COLUMN MANUFACTURING_PLANT_KEY NUMERIC(6,0) NOT NULL DEFAULT 0

, LEAD_TIME_PRODUCTION NUMERIC(2,0)  NOT NULL DEFAULT 0

, PRODUCT_CYCLE CHARACTER VARYING(15)  NOT NULL DEFAULT ‘ ‘::”NVARCHAR”

, PRODUCT_CLASS CHARACTER VARYING(2)  NOT NULL  DEFAULT ‘ ‘::”NVARCHAR” ;

 

Cleanup Table SQL Statements

GROOM TABLE BLOG.PRODUCT_DIM VERSIONS;

GROOM TABLE BLOG.PRODUCT_DIM;

GENERATE STATISTICS ON BLOG.PRODUCT_DIM;

 

Related References

IBM Knowledge Center, PureData System for Analytics, Version 7.2.1

IBM Netezza database user documentation, Netezza SQL command reference, ALTER TABLE

PureData / Netezza – What date/time ranges are supported by Netezza?

SQL (Structured Query Language), Date/Time ranges supported by Netezza
Date/Time ranges supported by Netezza

Here is a synopsis of the temporal ranges ( date, time, and timestamp), which Netezza / PureData supports.

Temporal Type

Supported Ranges

Size In Bytes

Date

A month, day, and year. Values range from January 1, 0001, to December 31, 9999. 4 bytes

Time

An hour, minute, and second to six decimal places (microseconds). Values range from 00:00:00.000000 to 23:59:59.999999. 8 bytes

Related References

Temporal data types

PureData System for Analytics, PureData System for Analytics 7.2.1, IBM Netezza database user documentation, Netezza SQL basics, Data types, Temporal data types

Netezza date/time data type representations

PureData System for Analytics, PureData System for Analytics 7.2.1, IBM Netezza user-defined functions, Data type helper API reference, Temporal data type helper functions, Netezza date/time data type representations

Date/time functions

PureData System for Analytics, PureData System for Analytics 7.2.1, IBM Netezza database user documentation, Netezza SQL basics, Netezza SQL extensions, Date/time functions

Netezza / PureData – How to add a Foreign Key

DDL (Data Definition Language), Netezza PureData How to add a Foreign Key
DDL (Data Definition Language)

Adding a forging key to tables in Netezza / PureData is a best practice; especially, when working with dimensionally modeled data warehouse structures and with modern governance, integration (including virtualization), presentation semantics (including reporting, business intelligence and analytics).

Foreign Key (FK) Guidelines

  • A primary key must be defined on the table and fields (or fields) to which you intend to link the foreign key
  • Avoid using distribution keys as foreign keys
  • Foreign Key field should not be nullable
  • Your foreign key link field(s) must be of the same format(s) (e.g. integer to integer, etc.)
  • Apply standard naming conventions to constraint name:
    • FK_<<Constraint_Name>>_<<Number>>
    • <<Constraint_Name>>_FK<<Number>>
  • Please note that foreign key constraints are not enforced in Netezza

Steps to add a Foreign Key

The process for adding foreign keys involves just a few steps:

  • Verify guidelines above
  • Alter table add constraint SQL command
  • Run statistics, which is optional, but strongly recommended

Basic Foreign Key SQL Command Structure

Here is the basic syntax for adding Foreign key:

ALTER TABLE <<Owner>>.<<NAME_OF_TABLE_BEING_ALTERED>>

ADD CONSTRAINT <<Constraint_Name>>_fk<Number>>

FOREIGN KEY (<<Field_Name or Field_Name List>>) REFERENCES <<Owner>>.<<target_FK_Table_Name>.(<<Field_Name or Field_Name List>>) <<On Update | On Delete>> action;

Example Foreign Key SQL Command

This is a simple one field example of the foreign key (FK)

ALTER TABLE Blog.job_stage_fact

ADD CONSTRAINT job_stage_fact_host_dim_fk1

FOREIGN KEY (hostid) REFERENCES Blog.host_dim(hostid) ON DELETE cascade ON UPDATE no action;

Related References

Alter Table

PureData System for Analytics, PureData System for Analytics 7.2.1, IBM Netezza database user documentation, Netezza SQL command reference, Alter Table, constraints