# `addFieldScript` (procedure)


- **Type:** PROCEDURE
- **Deterministic:** NO
- **SQL data access:** CONTAINS SQL

## Parameters

| # | Mode | Name | Type |
|---|---|---|---|
| 1 | IN | `sColumnName` | `varchar(100)` |
| 2 | IN | `sTableName` | `varchar(100)` |
| 3 | IN | `sType` | `varchar(100)` |
| 4 | IN | `sDefault` | `varchar(100)` |
| 5 | IN | `sIsNull` | `varchar(100)` |
| 6 | IN | `sComment` | `varchar(255)` |

## Body

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

## Narrative

**Business context:** DBA upgrade helper — adds a column to a table *idempotently* (no-op if the column already exists). Lives in the 2021-11-04 standalone backend upgrade bundle (`script/标版/upgrade/20211104单独升级后台包需要执行/`) where dozens of `quoquotationslave` cost-breakdown columns (印前/印刷/印后/主料/辅料/折扣 money + rate fields) get appended through it.

**What it does:** queries `information_schema.COLUMNS` for the `<sTableName, sColumnName>` pair in the current `DATABASE()`. If absent, builds an `ALTER TABLE ... ADD COLUMN` dynamic statement — synthesises a sensible `DEFAULT` clause per type family (`varchar`/`int`/`decimal`/`bit`/`datetime`), appends `sIsNull` and a `COMMENT` literal — then prepares/executes it. If the column already exists it returns silently.

**Invocation:** called from the upgrade script `script/标版/upgrade/20211104单独升级后台包需要执行/zAddFieldAppendPro.sql` (proc `scriptSqlProAppend`, ~30 column-adds against `quoquotationslave`). No live runtime caller, no form binding, no gdsmodule hook — strictly a migration helper. Status: maintained as part of upgrade tooling, not orphaned in the audit sense, but unused at runtime.