# `Fun_GetAddMapJson` (function)

> 组装MapJSON


- **Type:** FUNCTION
- **Returns:** `longtext`
- **Deterministic:** NO
- **SQL data access:** CONTAINS SQL

## Parameters

| # | Mode | Name | Type |
|---|---|---|---|
| 1 | IN | `p_JSON` | `longtext` |
| 2 | IN | `p_Cloumn` | `varchar(500)` |
| 3 | IN | `p_Value` | `varchar(1000)` |

## Body

_Body is not pre-cached. To inspect: `mysql --defaults-file=~/.my.cnf -e 'SHOW CREATE FUNCTION `Fun_GetAddMapJson`'`._

## Narrative

**Business context:** JSON-object builder — `组装MapJSON`. Appends a single `"key":"value"` pair to an existing JSON object (or creates a new one if empty), returning the merged JSON string.

**What it does:** strips `{` and `}` from `p_JSON` to gauge non-emptiness. If empty, returns `{"p_Cloumn":"p_value"}`. Otherwise, snips the trailing `}` off `p_JSON` and concatenates `,"p_Cloumn":"p_value"}`. Pure string manipulation — does not parse or validate JSON.

**Invocation:** Status: appears orphaned. No caller found in any channel (form-master sSqlStr, gdsmodule hooks, other routines, exhaustive xly-src grep, dynamic-dispatch search) — candidate for maintainer audit. MySQL's native `JSON_SET` / `JSON_OBJECT` are preferred elsewhere in the codebase.