Answers.Body: <p>If you know there's only one row you're interested in, you can execute the query with <a href="https://docs.craftcms.com/api/v3/craft-db-query.html#method-one" rel="nofollow noreferrer"><code>.one()</code></a> instead of <code>.array()</code>, this will give you a single result row as an associative array instead of an array of rows. In your case, since you're only interested in a single column, you can also use <a href="https://docs.craftcms.com/api/v3/craft-db-query.html#method-scalar" rel="nofollow noreferrer"><code>.scalar()</code></a> to return that column directly as a string. Once you have the string, you can decode the JSON string using the <a href="https://craftcms.com/docs/3.x/dev/filters.html#json-decode" rel="nofollow noreferrer"><code>json_decode</code> filter</a>. Then you can access the value you're interested in.</p>
  <p>To handle the case where the result row doesn't exist, check if the query didn't return <code>null</code> or <code>false</code> before attempting to decode the result.</p>
  <pre class="lang-twig prettyprint-override"><code>{% set orderFields = craft.query()
      .select('response')
      .from('commerce_transactions')
      .scalar()
  %}
  {% set orderFields = orderFields ? orderFields|json_decode : null %}
  {% set pmethod = orderFields ? orderFields.pmethod : null %}
  </code></pre>
  <p><strong>Query filtering</strong></p>
  <p>Your query doesn't apply any conditions or sorting, so it will just fetch ALL transactions (which might be a huge dataset once you have a couple of customers). Or if you're executing the query with <code>.scalar()</code> or <code>.one()</code>, it will give you just one (essentially) random row as the result.</p>
  <p>In order to get the row you need, you need to add conditions to the query that uniquely identify that row. For a start, you can filter by rows that have the text <code>01</code> in their <code>code</code> field:</p>
  <pre class="lang-twig prettyprint-override"><code>{% set orderFields = craft.query()
      .select('response')
      .from('commerce_transactions')
      .where(['code' =&gt; '01'])
      .scalar()
  %}
  </code></pre>
  <p>Since most of the data in that table is contained in the string as JSON, filtering based on that might be a little difficult. In this case, you can also fetch multiple transactions and then use the <a href="https://twig.symfony.com/doc/3.x/filters/filter.html" rel="nofollow noreferrer"><code>filter</code> filter</a> to find the one you need. Something like this:</p>
  <pre class="lang-twig prettyprint-override"><code>{% set orderFields = craft.query()
      .select('response')
      .from('commerce_transactions')
      .all()
      |map(row =&gt; row | json_decode)
  %}
  {% set orderFieldWithPaymentInfo = orderFields
      |filter(row =&gt; row.authorizationCode == '534711419')
      |first
  %}
  {% set pmethod = orderFieldWithPaymentInfo.pmethod %}
  </code></pre>
  <hr />
  <p>This method is really error-prone and I don't think it's the right approach. Craft Commerce provides services and and hooks to access data (such as transactions) at specific points in the order process, and you should probably use those. It's rarely necessary to bypass those APIs and query the database directly. This is bad practice in particular because then you're tightly coupling your plugin logic to implementation details of Craft Commerce that might change at any point.</p>
  <p>Take a look at the <a href="https://craftcms.com/docs/commerce/3.x/" rel="nofollow noreferrer">documentation for Craft Commerce</a> to find the best way to get the data you're looking for.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-14T04:56:16.463Z
Answers.Text: i get en error, "Key "pmethod" for array with keys "amount, currency,..." does not exist. Is this because, in the first row/item in the table, there is no pmethod in the json object? only every second/third row has this pmethod (they have "success" in the status column).
Answers.UserDisplayName: Henrik
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-14T07:29:20.870Z
Answers.Text: @Henrik Yes, `scalar()` returns the first column of the first row that matches so query, so if that one doesn't contain the `pmethod` field you'll get an error. In this case, either adjust your query to only find the row you're looking for, or execute the query with [`column()`](https://docs.craftcms.com/api/v3/craft-db-query.html#public-methods) instead. This will return an array of strings, then you can iterate through that to find the row you're looking for.
Answers.UserDisplayName: MoritzLost
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-14T13:18:19.143Z
Answers.Text: thanks. getting a bit lost here. with 'column()' you mean the twig filter?  so i have to set another variable from orderFields? or how can i adjust the query to get the row i am looking for?
Answers.UserDisplayName: Henrik
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-14T14:00:07.050Z
Answers.Text: @Henrik No, I mean execute the query with `column()`. See [this method here](https://docs.craftcms.com/api/v3/craft-db-query.html#method-column). Instead of putting `scalar()` at the end of your query, use `column()`. This will return an array of rows that match the query. It's difficult to find a good solution without the larger picture. Maybe post some additional context to your question – where does the data come from, and who puts it there? Why are there multiple rows that match your query? What exactly are you looking for there?
Answers.UserDisplayName: MoritzLost
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-14T14:00:57.857Z
Answers.Text: @Henrik You can probably add additional conditions to the query so it only finds exactly the row you're looking for. But without knowing the context I can't tell you what those conditions may be.
Answers.UserDisplayName: MoritzLost
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-20T07:43:23.063Z
Answers.Text: a added additional info to my question, hope it opens up a larger picture of what i try to achieve... so in theory, i have to get all row with the code column of "01" first, then get into the "response" column to get the pmethod key, right?
Answers.UserDisplayName: Henrik
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-20T10:38:46.273Z
Answers.Text: @Henrik Yes, sounds right. I've added some examples on how to apply this condition to the query and/or filter the result set further if needed. Though I don't think you're on the right track with that query, there's probably an easier way to access the data you're looking for using the API provided by Craft Commerce.
Answers.UserDisplayName: MoritzLost
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-13T10:03:43.083Z
Answers.LastActivityDate: 2022-04-20T10:36:47.410Z
Answers.LastEditDate: 2022-04-20T10:36:47.410Z
Answers.UserDisplayName: MoritzLost
Body: <p>in commerce, all transactions are written into the database, into the table &quot;commerce_transactions&quot;. every transactions will result in a row, where different data is the stored into columns.
  (id, gateway, amount, ..).</p>
  <p>i have a plugin which provides a gateway for a swiss payment provider. When somebody pays over this gateway a column called &quot;response&quot; is filled with a json object, which includes also the amount, the id, and pmethod (basically which card is used).</p>
  <p>short example:</p>
  <p>{&quot;currency&quot;:&quot;CHF&quot;,&quot;amount&quot;:&quot;6000&quot;,&quot;pmethod&quot;:&quot;PFC&quot;,&quot;status&quot;:&quot;success&quot;}</p>
  <p>because of a redirect, each transaction results in two rows.
  i am interested in the row, which has a 01 in the code column, because only this row has the &quot;pmethod&quot; key in the &quot;response&quot; column. (see screenshot)
  <a href="https://i.sstatic.net/x2xCb.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/x2xCb.png" alt="enter image description here" /></a></p>
  <p>i get the data with this:</p>
  <pre><code>{% set orderFields = craft.query().select('response').from('commerce_transactions').all() %}
  </code></pre>
  <p>but i need only one key from the object, the pmethod. i want to output &quot;PFC&quot;, or whatever is written there for outputting it via twig in the confirmation customer email.</p>
  <p>how do i get this one key pair?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-04-13T08:25:23.660Z
Comments.Text: What is the query returning at the moment? Try putting `{% dd orderFields %}` in there to see the result of the query. Also, what kind of column is this `response`, a custom column in a custom table or a regular field of an entry?
Comments.UserDisplayName: MoritzLost
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-04-13T08:26:35.310Z
Comments.Text: its a custom column of a custom table.
Comments.UserDisplayName: Henrik
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-04-13T08:30:23.073Z
Comments.Text: Can you post the result of the `dd` statement? Also, try using `asArray()` on the query and/or `one()` instead of `.all()`.
Comments.UserDisplayName: MoritzLost
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-04-13T08:30:51.250Z
Comments.Text: the result of the query via dd (shortened version):
  [
      0 => [
          'response' => '{\"amount\":\"3192\",\"pmethod\":\"ECA\",\"status\":\"success\"}'
      ]
  ]
Comments.UserDisplayName: Henrik
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-04-13T08:35:20.950Z
Comments.Text: .asArray() gives me an error: Calling unknown method: craft\db\Query::asArray()
Comments.UserDisplayName: Henrik
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-04-13T10:04:17.827Z
Comments.Text: Ah ok, asArray doesn't exist because it's not element query, so it isn't populated in the first place. Anyway, I've added an answer that should work below.
Comments.UserDisplayName: MoritzLost
Tags: <plugin-craftcommerce><database><json>
Title: How to retrieve (& output via twig) one key pair of json object stored i a database column
ThreadText: # How to retrieve (& output via twig) one key pair of json object stored i a database column
  
  (Asked by: username_0 on 2022-04-13)
  
  in commerce, all transactions are written into the database, into the table "commerce\_transactions". every transactions will result in a row, where different data is the stored into columns.
  (id, gateway, amount, ..).
  
  i have a plugin which provides a gateway for a swiss payment provider. When somebody pays over this gateway a column called "response" is filled with a json object, which includes also the amount, the id, and pmethod (basically which card is used).
  
  short example:
  
  {"currency":"CHF","amount":"6000","pmethod":"PFC","status":"success"}
  
  because of a redirect, each transaction results in two rows.
  i am interested in the row, which has a 01 in the code column, because only this row has the "pmethod" key in the "response" column. (see screenshot)
  [![enter image description here](https://i.sstatic.net/x2xCb.png)](https://i.sstatic.net/x2xCb.png)
  
  i get the data with this:
  
  ```
  {% set orderFields = craft.query().select('response').from('commerce_transactions').all() %}
  
  ```
  
  but i need only one key from the object, the pmethod. i want to output "PFC", or whatever is written there for outputting it via twig in the confirmation customer email.
  
  how do i get this one key pair?
  
  **Tags:** plugin-craftcommerce, database, json
  
  > **Comments:**
  > **username_1**: What is the query returning at the moment? Try putting `{% dd orderFields %}` in there to see the result of the query. Also, what kind of column is this `response`, a custom column in a custom table or a regular field of an entry?  
  > **username_0**: its a custom column of a custom table.  
  > **username_1**: Can you post the result of the `dd` statement? Also, try using `asArray()` on the query and/or `one()` instead of `.all()`.  
  > **username_0**: the result of the query via dd (shortened version): [     0 => [         'response' => '{\"amount\":\"3192\",\"pmethod\":\"ECA\",\"status\":\"success\"}'     ] ]  
  > **username_0**: .asArray() gives me an error: Calling unknown method: craft\db\Query::asArray()  
  > **username_1**: Ah ok, asArray doesn't exist because it's not element query, so it isn't populated in the first place. Anyway, I've added an answer that should work below.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2022-04-13. Score: 3
  
  If you know there's only one row you're interested in, you can execute the query with [`.one()`](https://docs.craftcms.com/api/v3/craft-db-query.html#method-one) instead of `.array()`, this will give you a single result row as an associative array instead of an array of rows. In your case, since you're only interested in a single column, you can also use [`.scalar()`](https://docs.craftcms.com/api/v3/craft-db-query.html#method-scalar) to return that column directly as a string. Once you have the string, you can decode the JSON string using the [`json_decode` filter](https://craftcms.com/docs/3.x/dev/filters.html#json-decode). Then you can access the value you're interested in.
  
  To handle the case where the result row doesn't exist, check if the query didn't return `null` or `false` before attempting to decode the result.
  
  ```twig
  {% set orderFields = craft.query()
      .select('response')
      .from('commerce_transactions')
      .scalar()
  %}
  {% set orderFields = orderFields ? orderFields|json_decode : null %}
  {% set pmethod = orderFields ? orderFields.pmethod : null %}
  
  ```
  
  **Query filtering**
  
  Your query doesn't apply any conditions or sorting, so it will just fetch ALL transactions (which might be a huge dataset once you have a couple of customers). Or if you're executing the query with `.scalar()` or `.one()`, it will give you just one (essentially) random row as the result.
  
  In order to get the row you need, you need to add conditions to the query that uniquely identify that row. For a start, you can filter by rows that have the text `01` in their `code` field:
  
  ```twig
  {% set orderFields = craft.query()
      .select('response')
      .from('commerce_transactions')
      .where(['code' => '01'])
      .scalar()
  %}
  
  ```
  
  Since most of the data in that table is contained in the string as JSON, filtering based on that might be a little difficult. In this case, you can also fetch multiple transactions and then use the [`filter` filter](https://twig.symfony.com/doc/3.x/filters/filter.html) to find the one you need. Something like this:
  
  ```twig
  {% set orderFields = craft.query()
      .select('response')
      .from('commerce_transactions')
      .all()
      |map(row => row | json_decode)
  %}
  {% set orderFieldWithPaymentInfo = orderFields
      |filter(row => row.authorizationCode == '534711419')
      |first
  %}
  {% set pmethod = orderFieldWithPaymentInfo.pmethod %}
  
  ```
  
  ---
  
  This method is really error-prone and I don't think it's the right approach. Craft Commerce provides services and and hooks to access data (such as transactions) at specific points in the order process, and you should probably use those. It's rarely necessary to bypass those APIs and query the database directly. This is bad practice in particular because then you're tightly coupling your plugin logic to implementation details of Craft Commerce that might change at any point.
  
  Take a look at the [documentation for Craft Commerce](https://craftcms.com/docs/commerce/3.x/) to find the best way to get the data you're looking for.
  
  > **Comments:**
  > **username_0**: i get en error, "Key "pmethod" for array with keys "amount, currency,..." does not exist. Is this because, in the first row/item in the table, there is no pmethod in the json object? only every second/third row has this pmethod (they have "success" in the status column).  
  > **username_1**: @username_0 Yes, `scalar()` returns the first column of the first row that matches so query, so if that one doesn't contain the `pmethod` field you'll get an error. In this case, either adjust your query to only find the row you're looking for, or execute the query with [`column()`](https://docs.craftcms.com/api/v3/craft-db-query.html#public-methods) instead. This will return an array of strings, then you can iterate through that to find the row you're looking for.  
  > **username_0**: thanks. getting a bit lost here. with 'column()' you mean the twig filter?  so i have to set another variable from orderFields? or how can i adjust the query to get the row i am looking for?  
  > **username_1**: @username_0 No, I mean execute the query with `column()`. See [this method here](https://docs.craftcms.com/api/v3/craft-db-query.html#method-column). Instead of putting `scalar()` at the end of your query, use `column()`. This will return an array of rows that match the query. It's difficult to find a good solution without the larger picture. Maybe post some additional context to your question – where does the data come from, and who puts it there? Why are there multiple rows that match your query? What exactly are you looking for there?  
  > **username_1**: @username_0 You can probably add additional conditions to the query so it only finds exactly the row you're looking for. But without knowing the context I can't tell you what those conditions may be.  
  > **username_0**: a added additional info to my question, hope it opens up a larger picture of what i try to achieve... so in theory, i have to get all row with the code column of "01" first, then get into the "response" column to get the pmethod key, right?  
  > **username_1**: @username_0 Yes, sounds right. I've added some examples on how to apply this condition to the query and/or filter the result set further if needed. Though I don't think you're on the right track with that query, there's probably an easier way to access the data you're looking for using the API provided by Craft Commerce.  
  
  ---
  
  