lookup

问题 Process p = Runtime.getRuntime().exec("screencap -p /storage/sdcard0/test3332.png"); p.waitFor(); String error = "error: " + p.exitValue(); p.exitValue() is equal to 11 How to get the "meaning" or message from this exit code? If this should be available in the command's manual, then where to find this manual? Can someone post a link or a reference ? 回答1: The error message can be retrieved in this way: int ch; StringBuilder sb = new StringBuilder(); while((ch = p.getErrorStream().read()) != -1

来源： https://stackoverflow.com/questions/43257795/java-8-convert-list-to-lookup-map

来源： https://stackoverflow.com/questions/43257795/java-8-convert-list-to-lookup-map

来源： https://stackoverflow.com/questions/43257795/java-8-convert-list-to-lookup-map

来源： https://stackoverflow.com/questions/41113781/processing-hive-lookup-tables-in-spark-vs-spark-broadcast-variables

来源： https://stackoverflow.com/questions/41113781/processing-hive-lookup-tables-in-spark-vs-spark-broadcast-variables

来源： https://stackoverflow.com/questions/63865211/why-is-this-code-saying-type-number-is-not-assignable-to-type-never

来源： https://stackoverflow.com/questions/63769147/lookup-all-cells-of-one-row-in-another-df-and-return-flag-if-all-exist-using-pan

来源： https://stackoverflow.com/questions/42981282/lookup-data-in-powerpivot-model-facttables-from-excel

问题 This question already has answers here : Multiple join conditions using the $lookup operator (4 answers) Closed 2 years ago . I'd like to "join" 3 Collections in MongoDB by using mongochef. The collections are "Order", "Employee" and "City". I tried to use temp collections, but it is not effective. Now I am using var = a for the first "join". If I 'd like to show "a", there are displayed 20 results only. Do you have an idea or another solution? var a = db.Order.aggregate([ { $lookup: { from: