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VillageSQL is a drop-in replacement for MySQL with extensions.

All examples in this guide work on VillageSQL. Install Now →
Summarization converts long text into a shorter version that captures the key points. Support tickets, customer feedback, articles, and log entries all benefit from a short summary field that lets you scan content quickly. MySQL has no summarization function. VillageSQL’s ai_prompt() adds one.

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With VillageSQL: Summaries in SQL

INSTALL EXTENSION vsql_ai;
A summarization prompt specifies the desired length and what to keep: 
SET @key = 'sk-ant-your-api-key';

ALTER TABLE support_tickets ADD COLUMN summary VARCHAR(500);

SET SESSION max_execution_time = 300000;

UPDATE support_tickets
SET summary = ai_prompt(
    'anthropic',
    'claude-haiku-4-5-20251001',
    @key,
    CONCAT(
        'Summarize this support ticket in one sentence. ',
        'Include the main issue and any resolution mentioned.\n\n',
        'Ticket: ', body
    )
)
WHERE summary IS NULL
LIMIT 100;
Query summaries like any other column — no AI call at read time: 
-- Recent tickets with AI summaries for quick triage
SELECT id, created_at, summary
FROM support_tickets
WHERE created_at > NOW() - INTERVAL 24 HOUR
ORDER BY created_at DESC;

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Structured summaries

For use cases where you need to extract specific fields, ask for JSON output: 
ALTER TABLE support_tickets ADD COLUMN ai_extract JSON;

UPDATE support_tickets
SET ai_extract = ai_prompt(
    'anthropic',
    'claude-haiku-4-5-20251001',
    @key,
    CONCAT(
        'Extract key information from this support ticket. ',
        'Return JSON with keys: issue (string), urgency (low/medium/high), ',
        'product_mentioned (string or null), resolution_needed (boolean). ',
        'Return only valid JSON.\n\n',
        'Ticket: ', body
    )
)
WHERE ai_extract IS NULL
LIMIT 100;

-- Triage: high-urgency tickets with no resolution
SELECT id, body,
       JSON_UNQUOTE(JSON_EXTRACT(ai_extract, '$.issue')) AS issue,
       JSON_UNQUOTE(JSON_EXTRACT(ai_extract, '$.product_mentioned')) AS product
FROM support_tickets
WHERE JSON_UNQUOTE(JSON_EXTRACT(ai_extract, '$.urgency')) = 'high'
ORDER BY created_at DESC;

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Summarizing multi-column content

Build richer context for the model by joining multiple fields: 
UPDATE articles
SET summary = ai_prompt(
    'anthropic',
    'claude-haiku-4-5-20251001',
    @key,
    CONCAT(
        'Write a two-sentence summary of this article for a preview card.\n\n',
        'Title: ', title, '\n',
        'Author: ', author_name, '\n',
        'Body: ', LEFT(body, 3000)   -- trim very long bodies
    )
)
WHERE summary IS NULL
LIMIT 50;
LEFT(body, 3000) avoids sending excessively long text to the model. Most AI models have a token limit; for very long documents, summarize the first few thousand characters or chunk the content.

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Length and Style Control

Prompt phrasing controls output length and tone:
GoalPrompt phrasing
One sentence”Summarize in one sentence.”
Tweet-length”Summarize in 280 characters or fewer.”
Executive summary”Write a 2–3 sentence executive summary.”
Bullet points”Summarize as 3 bullet points.”
Action-oriented”What does this ticket ask us to do? One sentence.”
For summaries used in UI previews, specify a character limit to avoid overflow.

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Model Selection

Summarization is generally well-handled by faster, cheaper models. Use claude-haiku-4-5-20251001 or gpt-4o-mini for bulk summarization. Step up to claude-sonnet-4-5-20250929 when:
  • The source text is long and complex
  • You need structured JSON extraction with nuanced fields
  • Accuracy of extracted facts matters more than cost
For setup and provider options, see Connecting MySQL to AI APIs.

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Frequently Asked Questions

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How long can the source text be?

Practical limit is a few thousand words per call. AI models have token limits (typically 100K–200K tokens for current models), but very long inputs cost more and take longer. For documents over ~5000 words, summarize the first section or chunk and summarize each chunk.

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Can I use summaries in a full-text search index?

Yes — add a FULLTEXT index on the summary column after populating it. Summaries are often better targets for full-text search than raw content because they’re shorter and more keyword-dense.

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Will the same document always produce the same summary?

No — AI models are probabilistic. The same prompt can produce slightly different output on different calls. If consistency matters, generate the summary once and store it; don’t regenerate on each read.

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How do I summarize rows that have already been summarized?

Don’t re-summarize unless the source content changed. Use WHERE summary IS NULL to only process new or updated rows. If you need to track changes, add a summary_updated_at column and compare it to the content’s last-modified timestamp.

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Troubleshooting

ProblemSolution
FUNCTION ai_prompt does not existRun INSTALL EXTENSION vsql_ai
Returns NULLCheck API key, max_execution_time, and model name
Summary too long or shortTighten the prompt: specify a character or sentence limit
Model repeats the source text instead of summarizingAdd “Do not copy sentences from the original” to the prompt
Structured JSON extraction has missing keysAdd “If a field is not mentioned, use null” to the prompt