How Can I Select Data from Columns with Similar Prefixes in a SQL Database?

Extracting Data from Columns with Similar Prefixes

As database users often encounter tables with numerous columns sharing similar naming conventions, extracting specific data based on these prefixes can be challenging. Consider a table with columns like "Vegetable_Name," "Fruit_Name," and "Meat_Name."

In attempting to select all information related to a specific food group, a user tried:

<code class="sql">$Food = "Vegetable";
mysql_query("SELECT `" . $Food . "%` FROM `Foods`");</code>

However, this query proved ineffective. To address this issue, it is necessary to dynamically construct the SQL query based on the desired prefix.

Dynamic SQL Query Generation

To retrieve the desired columns, follow these steps:

1. Extract Column Names: Execute the following SQL statement to retrieve the names of all columns that start with the specified prefix:

<code class="sql">SELECT COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE table_name = 'Foods'
    AND table_schema = 'YourDB'
    AND column_name LIKE 'Vegetable%'</code>

2. Construct Query String: Based on the retrieved column names, construct the SELECT query dynamically, using the appropriate table name and column name list.

Example:

Assume the retrieved column names are "Vegetable_Name" and "Vegetable_Type." The following query would select data from these columns:

<code class="sql">SELECT Vegetable_Name, Vegetable_Type
FROM Foods</code>

This approach allows for efficient and targeted data retrieval, even for tables with multiple columns sharing similar prefixes.

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