Method DropColumn

catalog/table.go:311–346

DropColumn implements sql.AlterableTable.

(ctx *sql.Context, columnName string)

		}
		sql += " DEFAULT " + defaultExpr
	} else if column.AutoIncrement {
		typ.mysql.AutoIncrement = true

		// Generate a random sequence name.
		uuid, err := uuid.NewRandom()
		if err != nil {
			return err
		}
		sequenceName = SequenceNamePrefix + uuid.String()
		createSequenceStmt, fullSequenceName = getCreateSequence(temporary, sequenceName)
		sqls = append(sqls, createSequenceStmt)

		defaultExpr := `nextval('` + fullSequenceName + `')`
		sql += " DEFAULT " + defaultExpr
	}

	sqls = append(sqls, sql)

	// DuckDB does not support constraints in ALTER TABLE ADD COLUMN statement,
	// so we need to add NOT NULL constraint separately.
	// > Parser Error: Adding columns with constraints not yet supported
	if !column.Nullable {
		sqls = append(sqls, `ALTER TABLE `+FullTableName(t.db.catalog, t.db.name, t.name)+` ALTER COLUMN `+QuoteIdentifierANSI(column.Name)+` SET NOT NULL`)
	}

	// Add column comment
	comment := NewCommentWithMeta(column.Comment, typ.mysql)
	sqls = append(sqls, `COMMENT ON COLUMN `+FullColumnName(t.db.catalog, t.db.name, t.name, column.Name)+` IS '`+comment.Encode()+`'`)

	// Add table comment if it is AUTO_INCREMENT or PRIMARY KEY
	tableInfo := t.comment.Meta
	tableInfoChanged := false
	if column.AutoIncrement {
		tableInfo.Sequence = fullSequenceName
		tableInfoChanged = true
	}
	if column.PrimaryKey {
		sqls = append(sqls, `ALTER TABLE `+FullTableName(t.db.catalog, t.db.name, t.name)+` ADD PRIMARY KEY (`+QuoteIdentifierANSI(column.Name)+`)`)
		tableInfo.PkOrdinals = []int{len(t.schema.Schema)}