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Where clause

As explained in Practical Automation with PowerShell: Effective scripting from the console to the cloud

A where clause is the SQL query clause that restricts returned rows according to conditions on column values.

A WHERE clause filters SQL query results by conditions on table columns. For automation, construct conditions dynamically while keeping values parameterized. section 7.4.1

Use parameterized conditions because they:

  • Validate data types and convert values such as DateTime into SQL formats. section 7.4.1
  • Escape special characters, reuse query plans, and reduce SQL injection risk. section 7.4.1

Parameterized server filter

Query Servers with `WHERE Name = @name`, then pass `@name` through Invoke-DbaQuery's SqlParameter hashtable instead of interpolating user input into the SQL string.

How Practical Automation with PowerShell: Effective scripting from the console to the cloud covers it

How deep it goes
Explains filtering, parameterization, injection risks, and dynamic function construction, but does not detail complete SQL condition syntax.
Examples
Uses server-name filtering, parameterized Invoke-DbaQuery calls, injection strings, and Get-PoshServer filter combinations.
What it assumes
Assumes SQL query and PowerShell familiarity while introducing SQL variables and SqlParameter hashtables.
What you can do after
Apply it via Invoke-DbaQuery and reusable PowerShell functions while avoiding unsafe string-built conditions.
How it connects
Connects SQL queries with SQL variables, Invoke-DbaQuery, PowerShell functions, hashtables, and SQL injection.
Cover of Practical Automation with PowerShell: Effective scripting from the console to the cloud
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