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How to add column if not exists on PostgreSQL?

...t pass these as parameters, you'll need to do variable substitution in the string on the client side, but this is a self contained query that only emits a message if the column already exists, adds if it doesn't and will continue to fail on other errors (like an invalid data type). I don't recommend...
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Determine if Android app is being used for the first time

...is over. This is my code to catch the first time you open the app: final String PREFS_NAME = "MyPrefsFile"; SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0); if (settings.getBoolean("my_first_time", true)) { //the app is being launched for first time, do something ...
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How does this checkbox recaptcha work and how can I use it?

... verify the "g-recaptcha-response" control is filled in: protected static string ReCaptcha_Key, ReCaptcha_Secret; protected void btnSubmit_Click(object sender, EventArgs e) { if (!String.IsNullOrEmpty(Request.Form["g-recaptcha-response"])) { // other code } else { lb...
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Set value to NULL in MySQL

...d'] == '')) { $val = 'NULL'; } else { $val = "'" . mysql_real_escape_string($_POST['nullfield']) . "'"; } $sql = "INSERT INTO .... VALUES ($val)"; if you put 'NULL' into your query, then you're just inserting a 4-character string. Without the quotes, NULL is the actual null value. ...
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Correct Bash and shell script variable capitalization

...ing), and relatively few 'locals' (counters, iterators, partly-constructed strings, and temporaries) share |
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What exactly does += do in python?

... # empty list x += "something" # iterates over the string and appends to list print(x) # ['s', 'o', 'm', 'e', 't', 'h', 'i', 'n', 'g'] versus x=[] # empty list x = x + "something" # TypeError: can only concatenate list (not "str") to list...
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Bootstrap 3 modal vertical position center

...io/anon/pen/Hiskj ..selecting this as the correct answer since there's no extra heavy javascript that brings the browser to its knees in case of more than one modals. share | improve this answer ...
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“Too many values to unpack” Exception

...no Borini, I am getting also similar error but in my case, I am creating a string as obj='{"vendorId": "' + vID +'", "vendorName" :"'+vName+'", "addedDate" : "'+vAddedDate+'","usersList" : "'+ usersList + '," status" : "'+str(vStatus)+'","edit"'+edit+'"}'; although all the values are string, it give...
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Android Use Done button on Keyboard to click button

...t" android:layout_height="wrap_content" android:hint="@string/prompt_unidades" android:inputType="number" android:maxLines="1" android:singleLine="true" android:textAppearance="?android:textAppearanceSmall" ...
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Redirect stdout to a file in Python?

... to replace the 'w' attribute with, os.O_WRONLY|os.O_CREATE ... can't send strings into the "os" commands! – Ch'marr Jul 26 '12 at 21:52 3 ...